PREOPERATIVE PLANNING AND PERIOPERATIVE MANAGEMENT

Cardiac disease, highly prevalent among many orthopaedic
patient populations, has a significant impact on perioperative
morbidity and mortality. Question patients specifically

about
chest pain and shortness of breath on moderate exertion, in addition to
any history of myocardial infarction. Physical examination findings
that may suggest congestive heart failure include jugular venous
distention, rales, or an S3 gallop.

Goldman developed a multifactorial risk index to stratify patients into low, medium, and high risk for cardiac complications (52,53) (Table 5.4 and Table 5.5).
Patients with unstable angina, severe aortic stenosis, or a 6-month
history of myocardial infarction are at highest surgical risk. Medical
evaluation of patients with cardiac disease may call for preoperative
echocardiograms and stress tests, which usually require advance
scheduling.

Mild to moderate hypertension per se has not been shown
to increase surgical risk, but it may be associated with other risk
factors, such as cardiac disease, that can contribute to perioperative
complications. Patients can continue to take most antihypertension
medications during the perioperative period. Carefully monitor the
volume status and electrolyte balance of patients taking diuretics.

Evaluate the pulmonary function of patients who smoke,
those who are morbidly obese, and those with asthma and chronic
pulmonary disease (99). Patients with significant hypercapnia (elevated CO₂) and an FeV₁ (forced expiratory volume in 1 sec) of less than 1 liter are at greatest risk of pulmonary complications (6).
Evaluation of postoperative arterial blood gas (ABG) results can be
difficult in these patients when there is a question of possible
pulmonary embolism. A baseline preoperative ABG is helpful if patients
become symptomatic after surgery.

A patient’s pulmonary function can be improved if she
stops smoking in the weeks preceding surgery. Preoperative instruction
in coughing and deep breathing exercises is also helpful. Use of
narcotic analgesics, which can depress the respiratory system, should
be minimized when

possible
to decrease postoperative pulmonary complications. The use of
continuous epidural anesthesia may be beneficial for patients with
pulmonary disease undergoing lower extremity surgery.

Atelectasis due to decreased pulmonary inspiratory
volumes, common in the postsurgical patient, may result in significant
problems for patients with underlying pulmonary disease. Use incentive
spirometry, and administer inhaled bronchodilating agents as soon as
any sign of bronchospasm develops.

Management of asthmatic patients often requires the use
of bronchodilators and inhaled corticosteroids. In some cases,
intravenous corticosteroids may also be indicated. Guidelines have been
set for the preoperative medication of asthmatic patients based on the
severity of their disease (Table 5.6) (71).

Patients with chronic renal insufficiency and end-stage renal disease are at increased risk for perioperative complications (75).
Volume status, blood pressure, and electrolyte abnormalities must be
carefully managed. These patients are at risk for developing
hyperkalemia leading to cardiac arrhythmias. Patients with end-stage
renal disease may have uremic platelet dysfunction leading to increased
bleeding and a higher risk of infection. Dosages of medications
excreted by the kidneys need to be adjusted in these patients. Avoid
the use of nephrotoxic medications, which might cause further renal
damage.

Acute renal failure may occur in any patient who becomes
severely volume depleted and hypotensive. The postsurgical risk is
particularly great in patients with limited reserve, such as the
elderly and those with diabetes, congestive heart failure, or
preexisting renal disease. Rhabdomyolysis leading to acute renal
failure is a risk in trauma patients who sustain a significant crush
injury or extremity ischemia. Laboratory findings include myoglobin in
the urine and elevated skeletal muscle creatine kinase. Treatment
includes alkalinization of the urine with sodium bicarbonate,
intravenous furosemide (Lasix), and intravenous mannitol. Carefully
monitor electrolytes because these patients may become hyperkalemic.

The risk of perioperative complications and death in
patients with liver disease increases with the severity of their
disease. Patients who have evidence of hepatic decompensation
(hypoalbuminemia, coagulopathy, ascites, encephalopathy) are at the
greatest risk. In patients with cirrhosis, the risk correlates with
Child’s classification. Elective surgery is contraindicated in patients
with decompensated cirrhosis (Child’s class C), acute alcoholic
hepatitis, and acute viral hepatitis. Patients with chronic hepatitis
without evidence of cirrhosis or hepatic decompensation generally do
not have an increased complication risk (42).

Consider preoperative evaluation of the coagulation
system in patients with liver disease, since they may also have
impaired hemostasis. Closely monitor the fluid status, electrolyte
balance, and blood pressure of these patients, and avoid using
potentially hepatotoxic medications. Disturbances in hepatic function
may lead to prolonged action of anesthetic agents that are metabolized
in the liver. Sedatives, narcotic analgesics, and intravenous induction
agents should be used with caution, as they may cause a prolonged
depression of consciousness and precipitate hepatic encephalopathy if
used in standard doses. Resistance to curare-like neuromuscular
blocking agents

may require large dosages for effectiveness, leading to problems with anesthetic reversal after surgery.

Patients with diabetes mellitus often have coexisting cardiac, renal, and neurologic disease (45).
A patient may have severe cardiac disease with a history of silent
myocardial infarctions without being aware of it. Patients with
diabetes mellitus also have increased risk for postoperative infections
and problems with wound healing. Most experts recommend that surgery be
done on diabetic patients early in the day to simplify insulin
administration and glucose monitoring (64).

Patients who take oral hypoglycemics to control their
diabetes are usually managed after surgery with fingerstick glucose
levels every 6 hours and a sliding-scale insulin dosage for blood
sugars greater than 250 mg/dl. It may be necessary to hold long-acting
oral hypoglycemics preoperatively to decrease the risk of hypoglycemia.

Insulin-dependent patients with type I juvenile onset
diabetes must be carefully monitored after surgery for development of
ketoacidosis. Type I diabetics require both insulin and glucose while
fasting. Provide intravenous fluids containing dextrose while they are
fasting and either sliding-scale subcutaneous or continuous intravenous
insulin. Patients with type II adult onset diabetes are not at risk for
ketoacidosis. They may be managed by either sliding-scale subcutaneous
or continuous intravenous insulin (45). While
many treatment regimens have been suggested for insulin-dependent
patients, on the morning of surgery we generally hold the patient’s
regular insulin and give one half of the usual dose of long-acting
insulin, while administering an intravenous infusion of 5% dextrose.

Patients with rheumatoid arthritis who have been treated
with steroids may require supplemental steroid doses for stress during
the perioperative period. Patients who have been treated with steroids
for a year prior to surgery may have suppression of the
hypothalamic-pituitary-adrenal axis. Normally, the adrenal glands
respond to surgical stress by producing additional corticosteroids,
equivalent to 300–400 mg of hydrocortisone per day, for the first 2
days after surgery. Patients whose adrenal response is

suppressed are unable to produce the necessary corticosteroids; without supplementation, they may develop an adrenal crisis.

Patients who take daily doses of prednisone of 7.5 mg or
more can be assumed to have adrenal suppression and require
perioperative steroids. These patients should receive hydrocortisone
hemisuccinate, 100 mg intravenously every 6–8 hours, beginning
preoperatively and continuing for 72 hours after surgery. Other
patients who may be at risk include those who have been on higher doses
of prednisone (20 mg daily) at some point during the year before
surgery, and even some patients who take chronic daily doses of less
than 7.5 mg. These patients should undergo a cosintropin (synthetic
adrenocorticotropic hormone) stimulation test to measure their adrenal
response. If a patient’s serum cortisol level rises above 20 mg/dl at 1
hour after injection of 25 units of cosintropin, then the adrenal axis
is not suppressed, and perioperative steroid supplementation is not
required (6) .

Patients with rheumatoid arthritis may also develop
severe disease of the cervical spine. Obtain lateral flexion and
extension radiographs of the cervical spine to rule out instability,
which could result in neurologic injury during intubation or operative
positioning.

Advances in the medical management of human
immunodeficiency virus (HIV) have extended the length of time before
infected patients advance to acquired immunodeficiency syndrome (AIDS).
It is expected that an increasing number of asymptomatic HIV-positive
patients will require orthopaedic surgical procedures. Issues
concerning the risk of transmission to the surgeon are addressed later
in this chapter (see the section on Surgeon’s Safety).

In the late 1980s and early 1990s, some surgeons
expressed concern that the suppressive effect of anesthesia and
surgical trauma on cellular immunity could be detrimental to the
immunologic competence of patients with HIV infection. Initial concerns
about potential disease progression as a result of surgery were based
mainly on emotional preconceptions and anecdotal misconceptions (129).

A more substantial concern has been the potential for an
increased postoperative infection rate in HIV-positive patients. In
general, the risk of postoperative infection in patients with HIV who
have not advanced to AIDS is not higher than that in the general
population (88). The risk of surgical
complications increases with the progression of disease. Factors
reported to have the greatest correlation with outcome risk are a
history of opportunistic infection, a CD4 level less than 200, a serum
albumin less than 25 g/l, and cutaneous anergy (88). In a review of orthopaedic surgery in the HIV-positive patient, Luck (88) provides a surgical-risk rating system (Table 5.7).
Attempts to correlate surgical outcome with CD4 lymphocyte counts alone
has provided conflicting results; it is now generally accepted that CD4
counts alone are not a predictor of poor surgical outcome.

The rate of early postoperative infection and wound
healing complications has been reported to be increased in patients
with AIDS, but it is generally not increased in patients who are HIV
positive without AIDS. In hemophilic patients, the incidence of late
infection of prosthetic joints has been reported to be increased in
patients who are also HIV positive, especially when their CD4 count is
less than 200 (119,148).
The incidence of late prosthetic joint infections in patients with
hemophilia was higher than in the general population prior to the HIV
pandemic. The infection risk may be even higher in the HIV-positive
hemophilic patient, but current studies have not shown a

statistically
significant increase. At this time, there are no data to show that this
risk applies to the HIV-positive nonhemophilic patient with a
prosthetic joint (88a).

Several interventions may improve the medical status of
patients with advanced-stage AIDS who must undergo surgery. Patients
who have an unacceptably low white blood cell count (absolute
polymorphonuclear leukocyte count < 1,000) may be treated with
granulocyte-stimulating factor. Measles, mumps, and rubella vaccine
should be updated 2 weeks before surgery in patients who are anergic (88).
Many of the medications used to suppress HIV and to provide prophylaxis
against AIDS-related opportunistic infections suppress bone-marrow
function (88). As a result, AIDS patients may have chronic anemia that may benefit from treatment with erythropoietin (62). Patients with thrombocytopenia (platelet count < 60,000) should receive a platelet transfusion immediately before surgery.

Protein and calorie malnutrition has a significant
effect on the healing of wounds and fractures, as well as on
immunocompetence (138). Protein-calorie
malnutrition is associated with depression of multiple aspects of the
immune system response, including decreases in polymorphonuclear
phagocytosis and bactericidal activity, circulating opsonins,
complement levels, cell-mediated immunity, lymphocyte blastogenic
responses to mitogen, number of T lymphocytes, function of T-helper
cells, new antibody synthesis, and secretory IgA levels (1).

Many severely malnourished patients require emergent
surgical intervention; they will likely benefit from increased
postoperative nutritional support. Trauma and elective surgery both
markedly increase a malnourished individual’s nutritional needs.

Cocaine abuse has become increasingly prevalent.
Withdrawal from cocaine is not medically dangerous; the half-life of
cocaine is approximately 90 min, allowing most surgery to be delayed
until after the period of acute intoxication. Cocaine abuse has been
associated with several cardiac complications, and chronic abuse may
accelerate coronary atherosclerosis, interstitial myocardial fibrosis,
and congestive heart failure. Chronic abuse may also lead to recurrent
pneumonia, pulmonary barotrauma, diffuse alveolar hemorrhage, and
asthma (140).

Opioid dependence may result from both prescribed and
illicit drug use. Patients with chronic preoperative pain may have
developed dependence on opioids, a class of drugs that includes heroin,
morphine, codeine, oxycodone, and meperidine. Withdrawal symptoms may
develop as the patient’s postoperative analgesia is reduced.

To make the diagnosis of opioid dependence, the physician must observe at least three signs and symptoms of opioid withdrawal (Table 5.8).
Treatment of opioid withdrawal may require methadone, a long-acting
opioid, from which the patient may be weaned in an outpatient drug
dependency program. Clonipine 0.1–0.3 mg may also be helpful in
reducing the signs of opioid withdrawal, especially in patients with
hypertension (140).

The abuse of benzodiazepines (lorazepam, alprazolam,
oxazepam, diazepam, and chlordiazepoxide) is extremely common and may
lead to physiologic dependence and withdrawal. Signs and symptoms of
withdrawal may include lethargy, ataxia, irritability, dysphoria,
fatigue, tremor, and, rarely, seizure. Place patients who develop
withdrawal symptoms on a longer-acting benzodiazepine (diazepam,
chlordiazepoxide), which can be slowly tapered over 6–12 weeks.
Propranolol, 20 mg every 6 hours, can be used for the treatment of
hypertension, tachycardia, and anxiety that may occur during
benzodiazepine withdrawal (140).

Packed red blood cells (PRBC) are prepared by removing
most of the plasma from a donor unit of whole blood. A unit of PRBC
contains the same amount of hemoglobin as a unit of whole blood, but
its hematocrit, depending on the preservative solution, is at least
doubled (to 70%). Transfusion of PRBC rather than whole blood allows
the recipient to receive the equivalent number of red cells without
unnecessary expansion of the plasma volume. The use of PRBC allows
blood banks to use supernatant cells and plasma to prepare other
components. Neither whole blood nor PRBC is sterilized, so any
plasma-or cell-associated organisms not detected by donor screening may
be transmitted to the recipient by transfusion of these products.

Transfusion with PRBC is indicated when tissue oxygen
delivery, particularly delivery to vital organs, is inadequate. A
threshold for transfusion based on a given hemoglobin level cannot be
set, since oxygen delivery depends on several factors, including
hemoglobin level, inspired oxygen concentration, cardiac output, and
pulmonary gas exchange. Increased cardiac output in a young, healthy
patient may easily compensate for a low hemoglobin level, but an older
patient with cardiac disease or one who is taking beta-blocker
medication may be unable to increase cardiac output and will require
transfusion.

Factors to consider when deciding whether a patient
requires a PRBC transfusion include the patient’s physiologic state,
underlying medical condition, ability to compensate for diminished
oxygen-carrying capacity, oxygen requirements of vital organs, and
ongoing and anticipated blood loss (5).

A single unit of fresh frozen plasma (FFP) contains the
plasma separated from one unit of whole blood obtained from a single
donor. It contains normal plasma levels of labile (factors V and VIII)
and stable clotting factors, albumin, and gamma globulin. ABO
compatibility testing is mandatory for all recipients, and Rh
compatibility testing is recommended for women of child-bearing age, as
the small number of red cells that may be present in an Rh-positive
unit could sensitize the Rh-negative patient. FFP is indicated for
patients with plasma coagulation factor deficiencies, including those
who are undergoing a massive transfusion and those with a heritable
coagulation factor deficiency or coagulopathy secondary to severe liver
disease. FFP is also indicated when immediate correction of
anticoagulation due to warfarin is required, for replacement
transfusion in plasmapheresis, for immunodeficient patients, and for
patients with thrombotic thrombocytopenic purpura. The approximate
volume of each unit of FFP is 200–175 cc. Larger-volume jumbo units,
approximately 400–600 cc, are obtained from a single donor using
apheresis. FFP should be administered immediately after thawing, with
the dose guided by coagulation testing.

The maximal effect of FFP declines within 2 to 4 hours after administration.

In 1998, the U.S. Food and Drug Administration licensed
solvent/detergent plasma. This component is prepared from pools of
2,500 donor units, and it is treated with a solvent, tri-(N-butyl)
phosphate, and a detergent, triton X-100, to inactivate lipid-enveloped
viruses, including hepatitis B, hepatitis C, and HIV. Its drawbacks
relate to the pooling process, which increases patient exposure to
non-lipid-enveloped viruses such as hepatitis A and parvovirus B19.
Solvent/detergent plasma is indicated for the rapid reversal of
warfarin anticoagulation and therapeutic plasma exchange for
microangiopathic hemolytic anemia. Its approximate volume is 200 cc and
it must be used within 24 hours of thawing.

Cryoprecipitate is prepared by collecting the
precipitate that forms during slow thawing of FFP at refrigerator
temperature. It contains fibrinogen, fibronectin, and factor VIII. One
unit of cryoprecipitate contains approximately 10 ml of plasma and an
average of 200 mg of fibrinogen, or 80–120 units of factor VIII
activity. Cryoprecipitate is especially useful as a source of
fibrinogen in consumptive coagulopathies. It is also indicated for the
treatment of patients with hypofibrinogenemia and those with mild
hemophilia A. Patients with severe classic hemophilia are treated with
factor VIII concentrate. In view of the changing availability of stored
coagulation products and the increased risk associated with the
administration of some of these products, we recommend consultation
with a hematologist for the treatment of any complex coagulopathy.

Platelets are supplied either as single-donation units
or in packs that contain a pool of platelets from about six to ten
donors. Administration of pooled platelets poses a greater infection
risk than does that of single-donor units. Pooled platelets are more
readily available, however, since they are easily obtained as a
component of whole blood donations. A more complex apheresis process
must be used to obtain a sufficient quantity of platelets from a single
donor.

Platelets must be stored in special containers that
permit oxygen exchange, and they must be preserved at room temperature
with constant agitation. Properly stored, they can be used for up to 5
days after collection. Platelet concentrates should be typed for ABO,
and because they are contaminated with red cells they should be tested
for the Rh antigen. One unit of platelets separated from a single unit
of whole blood contains at least 5.5×10¹⁰ platelets and usually raises the platelet count of a 70 kg patient by about 7,500×10⁹
platelets per liter. The increase in posttransfusion platelet count may
be far less than anticipated for a variety of reasons, including fever,
splenomegaly, rapid hemorrhage, disseminated intravascular coagulation,
and refractoriness due to formation of anti-HLA antibodies. It must be
appreciated that the best test for platelet effectiveness is cessation
of bleeding.

Platelet transfusion is indicated for bleeding that
results from thrombocytopenia. Massive transfusion—at least 20 units of
blood in a 24-hour interval—may result in generalized oozing, with
platelet counts lower than 80×10⁹/liter, suggesting the need
for platelet transfusion. The administration of platelets in this
setting should be based on documented platelet counts. Do not
administer platelets prophylactically except in the setting of
preoperative platelet deficiency—a platelet count of less than 10×10⁹/liter.
Patients who are actively bleeding, whose bleeding time is greater than
twice normal, and whose platelet count is less than 50×10⁹/liter should receive platelets. The preoperative platelet count of a surgical candidate should be at least 60–80×10⁹/liter.

Although significant strides have been made to ensure a
safe blood supply, the recognition of new transfusion-related
complications, and the inability to totally eradicate previously
recognized complications, reaffirms the admonition that blood should be
transfused only when absolutely necessary (11).
Most of the complications associated with transfusion of blood and
blood products are related to an immune response to incompatible units,
to an adverse physiologic response to transfusion, or to infectious
disease transmission (Table 5.9).

Safe transfusion practice requires strict policies with
meticulous guidelines for patient identification, blood collection and
labeling, pretransfusion testing, and transfusion administration and
monitoring. These policies are necessary to decrease the risk of human
error; a fatal transfusion reaction can occur from administration of an
improperly labeled specimen, confusion of specimens in the laboratory,
or transfusion of blood to the wrong patient.

The potential for disease transmission has been substantially reduced through donor education, medical and social

history review, exclusion of anonymous donors, and improved serologic
screening methods. Despite these improvements, risk of disease
transmission remains a concern with any blood transfusion. The greatest
threat to the safety of the blood supply is blood donation by
seronegative donors who are infectious but who have not yet undergone
seroconversion (131).

Although new techniques of testing, such as direct viral
detection tests, will improve the safety of the blood supply, it
remains unlikely that any test or combination of tests will ever
decrease the risk for disease transmission to zero (131).

The risk of infection and death associated with blood
transfusion cannot be completely eliminated, even with the best
screening methods. The goal of reducing the risks associated with
transfusions, therefore, is directly related to reducing the number of
transfusions required by surgical patients. The methods available for
minimizing blood transfusions include meticulous hemostasis in the
operative field, hypotensive anesthesia, hemodilution, use of prebanked
autologous blood, intraoperative and postoperative blood salvage, and
acceptance of a lower hematocrit “transfusion trigger.” Concern about
transmission of human immunodeficiency virus has heightened interest in
these methods for orthopaedic surgeons and their patients and has made
blood conservation an important part of every surgeon’s practice.

Blount highlighted the importance of careful
preoperative planning for osteotomies, stating that, “Nowhere in
surgery is preoperative meditation and careful planning of more value” (18). Numerous different types of osteotomies have been developed, which are described in Chapter 26, Chapter 27, Chapter 28, Chapter 29, Chapter 30, Chapter 31 and Chapter 32 and Chapter 104.
Careful planning of an osteotomy may permit multiple simultaneous
corrections, including length, rotation, angulation, and displacement.
An understanding of the normal mechanical axis and the anatomic axis of
the lower limb is an essential part of any planned osteotomy of the
lower limb (Fig. 5.3). Standing long-cassette radiographs may be necessary to plan the degree of correction required.

An osteotomy must be carefully planned and its steps
sequentially executed. When a blade plate is required, the preoperative
plan must identify the location where the cortical window for the
seating chisel will be placed, and its direction and depth. Because it
is difficult to control small proximal or distal fragments, in many
cases the path for the blade is best cut before you make any of the
osteotomy cuts. The osteotomy becomes the final step prior to the
planned fixation. Intraoperatively, confirm restoration of alignment
with fluoroscopy, using an electrocautery cord as a radiopaque “plumb”
line. Center one end of the cord over the femoral head and the other
over the ankle joint,

reproducing
the new mechanical axis. Then visualize the location where the
mechanical axis (electrocautery cord) crosses the knee joint and
compare it with the preoperative plans.

Kirschner (K-) wires inserted proximal and distal to the
planned osteotomy site can also serve as markers for rotational or
angular corrections. If a blade plate is to be used, K-wires may also
be used as alignment guides for placement of the seating chisel. You
can also score the cortical bone to judge rotational corrections. Figure 5.4 is an example of this technique applied to the distal femur.

Most manufacturers can supply clear acetate templates of
arthroplasty implants for preoperative planning. For total hip
arthroplasty, these templates allow the surgeon to plan the size and
position for the implants. Variables that should be considered include
the location of the hip center, the neck cut, the implant position, and
the anticipated implant neck length. Different implants provide varying
amounts of femoral offset, a factor that may influence abductor muscle
function. Further details of preoperative planning for total joint
arthroplasty are provided in Chapter 101, Chapter 102 and Chapter 103, Chapter 105, Chapter 106, Chapter 108 and Chapter 109.

Computer programs have also been developed to assist in
the preoperative planning of osteotomies and total joint replacement.
These systems require digitization of the radiographs. Once all the
data have been acquired, they offer the benefit of allowing the surgeon
to easily try different degrees of correction (143). In some cases, three-dimensional CT may be helpful to better visualize certain deformities or complex fractures (74).
Reconstruction models can also be made from CT data to assist in the
planning of extremely complex correction involving deformed bones or
joints (112). (See Chapter 17.)

Good preoperative planning permits surgeons to approach
the operation with an attitude of confidence and with the assurance
that they will be able to handle any contingencies or unexpected
complications. Establish a businesslike attitude in the operating room.
Lighthearted conversation and background music in the operating room
are appropriate in some circumstances but must not distract from the
conduct of the surgery. Distractions slow down the operating team and
may lead to inadvertent breaks in surgical technique and other errors.

Treat all personnel with respect. Public verbal abuse of
operating room staff because of perceived deficiencies is inappropriate
and unproductive. The operating team will perform most effectively and
most efficiently if you maintain a calm and dignified demeanor
throughout the case and if the procedure is approached in a methodical
and logical fashion.

Sharing the preoperative plan with operating room
personnel before the surgery is always beneficial. You are ultimately
responsible for the availability and condition of instruments and
implants. Although this responsibility is customarily delegated to the
nursing staff, in whole or in part, it is prudent to review with the
scrub nurse the instrument and implant setup immediately before the
case. It is helpful to talk through the planned surgery quickly with
the operating team before the surgical preparation to be certain that
everybody understands what is planned, all instruments are present and
functional, and appropriate implants are available.

The choice of anesthesia is usually left to the
anesthesiologist, who bases the decision on the requirements of the
surgery, patient safety, and patient desires (see Chapter 7).
It is important, however, for you to advise the anesthesiologist on the
requirements for the operation to be performed. In the upper extremity,
regional or local anesthesia frequently is used. General anesthesia is
used when the operation is too long for regional or local anesthesia or
when extremely delicate surgery, such as neurovascular anastomosis,
requires the patient to be very still.

The same applies to surgery of the lower extremity;
however, regional anesthesia by blocking multiple peripheral nerves is
used infrequently because multiple blocks are required and usually do
not provide sufficient anesthesia for the use of a tourniquet. If there
is no contraindication,

epidural
anesthesia works extremely well for lower extremity surgery,
particularly when performed in an ambulatory surgery unit, because the
anesthetic does not have the residual effects of general anesthesia.
Epidural anesthesia may also be used in conjunction with general
anesthesia. The pain relief provided by the epidural permits a
“lighter” general anesthesia and is useful postoperatively for pain
management. Epidural anesthesia may be combined with hypotensive
anesthesia in appropriately selected patients, resulting in less blood
loss, fewer transfusions, and a decreased rate of deep vein thrombosis (86,134).
Plan for the prophylaxis of perioperative deep venous thrombosis before
selecting epidural anesthesia, to avoid the risk of the patient’s
developing an epidural hematoma when low-molecular-weight heparin is
being concurrently administered (68,162).
Spinal anesthesia is equally effective but can not be readministered
easily if the surgical procedure takes longer than estimated. It can
provide a higher level of anesthesia, but the risk of complications
such as headaches is slightly increased.

When major blood loss is expected—such as in hip
reconstructive surgery, pelvic surgery, and spine surgery—hypotensive
anesthesia, when not contraindicated, is extremely useful to minimize
it. Use of hypotensive anesthesia requires a careful preoperative
workup of the patient; therefore, it is important to consult with the
anesthesiologist early.

The use of prophylactic antibiotics in clean orthopaedic
surgery remains controversial. In our hospital and in most institutions
in North America, prophylactic antibiotics are used when wound exposure
time is expected to be more than 2 hours, or when major orthopaedic
implants will be used. The antibiotic used most commonly for
prophylaxis in orthopaedic surgery is cefazolin (104).

Cefazolin is an inexpensive first-generation
cephalosporin that provides broad-spectrum gram-positive coverage; it
has a high peak serum level and a long half-life. We generally give 1 g
cefazolin sodium intravenously with the preoperative medications,
although some authors recommend an initial dose of 2 g to achieve a
higher antibiotic level in bone (157). If you plan to use a tourniquet, administer the antibiotic at least 5 minutes before it is inflated (12).

If vancomycin is required in the potentially allergic
patient, infuse it slowly over at least 1 hour to avoid anaphylactoid
reactions that can occur from rapid infusion. When there is a question
of possible infection, hold preoperative antibiotics until
intraoperative cultures are obtained. For operative procedures of
longer duration, administer an additional intraoperative dose of
antibiotics at approximately 4 hours.

Depending on the nature of the operative procedure,
continue antibiotics postoperatively, at 1 g every 8 hours for 24
hours; then discontinue. Some surgeons prefer to administer
prophylactic antibiotics for a longer period of time, but there is no
concrete evidence showing that longer duration is beneficial (106).
Other antibiotics may be required if there has been major prior
surgery, previous infection, or contamination. When the wound is large
or has been exposed for more than 2 hours, we thoroughly irrigate it
with a low-pressure mechanical irrigator with sterile normal saline,
followed by bacitracin solution, 25,000 units per liter of saline.

Antibiotics also may be added to the methylmethacrylate
in total joint surgery. Methylmethacrylate beads impregnated with
antibiotics have been advocated to treat open fractures and bone
infections. These applications are discussed in more detail in Chapter 12, Chapter 105, Chapter 106, Chapter 132, Chapter 133, and Chapter 135.

As important as the use of prophylactic antibiotics is the operating room environment (104).
The majority of postoperative wound infections are caused by airborne
contamination. The second most common source of organisms is the
patient, and the third is the surgical team. An operating room of
modern design with positive-pressure air flow is important. Maintain
good discipline in the operating room to minimize unnecessary
conversation, traffic, and movement. In particular, personnel moving in
and out of the operating room must avoid traveling directly through the
doors leading into the adjacent hallways; when possible, they should
pass through the substerile room that is present in most surgical
suites.

For orthopaedic surgery, we recommend that all operating
room personnel wear hoods to cover exposed hair. Masks must direct air
flow from the mouth and nose, away from the operative field. All
operating personnel must wear freshly laundered surgical scrub suits,
which include pants that are secured at the ankle to minimize fallout.
Wear double surgical gloves or similar coverage during the drape and
surgical procedures. Some surgeons recommend replacing outer gloves
following draping. After draping, one pair of gloves is satisfactory
for strictly soft-tissue surgery when implants are not used, although
most orthopaedic surgeons routinely double-glove. Gowns must be
impervious to water and must cover the back.

For major surgical procedures lasting longer than 2
hours and involving implants or large surgical exposures, a special
low-bacteria environment using either horizontal or vertical laminar
air flow or ultraviolet lamps may be preferable. If horizontal laminar
air flow is used, take care, especially in total knee arthroplasty, not
to impede the air flow onto the operative field. Turbulent or impeded
air flow may actually increase the rate of contamination.

The four most common positions for surgery are the supine, prone, and right and left lateral decubitus positions.

Specialized positions are used for surgery to the cervical spine,
shoulder, and low back (see specific chapters). The orthopaedic table
is used to position patients for internal fixation of hip fractures,
femur fractures, fractures of the tibia, and other special situations.

Positioning is the responsibility of the
anesthesiologist and the surgeon. Particularly when the patient will
undergo a prolonged procedure, take care to avoid putting pressure on
neurovascular structures, muscle compartments, and bony prominences.
Position the patient to allow free expansion of the thoracic cavity and
movement of the diaphragm. Place gel or foam pads in areas of high
pressure concentration to avoid injury to the skin.

Use of a tourniquet greatly facilitates extremity
surgery; it provides a bloodless field, which is essential for most
surgery of the hand and foot. There are, however, potential dangers
associated with the use of the tourniquet, and you must be familiar
with its proper use. Use a constant-pressure-regulated tourniquet that
is inflated with nitrogen. We apply it only to the upper arm and
proximal thigh (finger and toe tourniquets fashioned from Penrose
drains are described in the chapters on hand surgery). Even with
modern, reliable pneumatic tourniquets, it is possible to apply
excessive pressure. Use a calibration gauge to check the accuracy of
tourniquet pressure readings before each use.

Tourniquets are available in various lengths and widths
for various sizes of extremities. The pressure pattern produced by a
tourniquet is cone shaped, diminishing in width as the depth of the
extremity is reached. Therefore, wide tourniquets are necessary for
large extremities; do not use narrow tourniquets on large limbs (60).

Ask patients to clip and clean the nails of the affected
limb before surgery, and to remove nail polish. Warn them to avoid
activities for 3 weeks before surgery that could cause minor scratches
and abrasions to the affected extremity. For clean individuals, special
bathing before surgery is not necessary. Shaving in advance of the
actual time of the surgery is contraindicated because of the risk of
accidental nicking of the skin. Razor cuts more than a few hours old
may harbor bacteria. Shaving and prepping in most hospitals are
performed in the operating room immediately before the surgery,
preferably in a preoperative preparation room to avoid contaminating
the operating suite with hair. If shaving must be done in the operating
room, do it wet to avoid aerosolizing hair, which may contaminate the
surgical instruments. Because shaving increases bacterial production
from sweat and sebaceous glands, shave only the immediate area of the
surgical incision. It is usually not necessary to shave the entire
extremity.

The technique, methods, and solutions used in the
preparation of the skin for surgery are variable and remain
controversial. The most commonly used skin-preparation solutions are
halogen agents that contain organic iodides such as povidone-iodine
soap and solution. Most surgeons prefer to defat the skin and remove
loose skin debris with a 5- to 10-minute scrub with soap using sterile
sponges and gloves.

To avoid contamination of the limb during draping, lay
the extremity on a sterile sheet or have an assistant support it using
sterile gloves or towels. This maneuver is exceedingly difficult with
heavy extremities that are unstable because of fractures. Take care to
avoid contamination, particularly proximally.

There are many different satisfactory draping routines.
We present general guidelines for satisfactory draping and three
typical draping routines: one for the upper or lower extremity, one for
the shoulder, and one for the hip. They use the standard sheets
available in an average general surgery pack without specialized split
and extremity sheets as well.

Although it is possible for one person to drape a
patient satisfactorily, ideal technique requires three people. One
assistant supports the extremity and maintains its sterility as it is
being draped, and the other two obtain the draping materials from the
back table and deploy them. Perform draping after the scrub nurse,
surgeon, and assistant are fully gloved and gowned. Drape with double
gloves, because inadvertent contamination can occur. Strip off the
outer set of gloves after the drape and put on a new second set for the
procedure.

Gentle, atraumatic, rapid, soft-tissue surgical
technique with good hemostasis is essential for good results. Straight
skin incisions generally provide the best exposure, the least risk of
skin necrosis, and the best cosmetic results. Incisions can be
longitudinal between the joints and over the extensor surface of
joints. Over the flexor surface of joints, incisions must be
transverse. When it is necessary to extend incisions that cross the
flexor surface of joints, make curvilinear ones. In the torso, follow
Langer’s lines (see Chapter 1, Chapter 2 and Chapter 3). Hoppenfeld and deBoer’s text, Surgical Exposures in Orthopaedics, provides numerous detailed drawings and descriptions of various surgical approaches as well (67).

Make skin incisions with a fresh scalpel blade and never
with a pair of scissors or cutting current. For easy closure and best
cosmetic results, make incisions at right angles to the skin. It is
often difficult in orthopaedic procedures when dealing with very
irregular surfaces to make such incisions. Take care to remain at right
angles to the skin even as the incision curves across the surface of
the limb.

After you have made the initial cut, continue dissection
with a sharp knife. Avoid blunt spreading with scissors or
electrocautery, which adds to soft-tissue damage. In certain areas
where subcutaneous and muscle hemorrhage is a particular problem, as in
the spine, electrocautery is used more frequently with minimal
morbidity. Rapid, precise dissection with the scalpel where tissues
must be cut, and blunt dissection with the finger or an elevator where
tissue planes can be split bluntly, is the most atraumatic and rapid
technique. Dissection with the scalpel, particularly in the region of
important neurovascular bundles, requires precise knowledge of anatomy.
Neurovascular bundles can be safely dissected out with a #15 blade if
the surgeon knows the anatomy and works from proximal to distal to
avoid cutting into the axillae of nerve and vascular branches. The good
surgeon treading in an anatomic region that she visits infrequently
will greatly improve her surgical technique by thoroughly reviewing the
anatomy and surgical approach before surgery.

In the lateral approach to the hip, it is common
practice to use a curved Mayo scissors to split the fascia lata and
expose the posterior border of the tensor fascia lata muscle, but this
is totally unnecessary. The surgeon wastes time in switching from the
knife to the scissors and back again. Most scissors are too dull and
result in slow, traumatic surgery. The knife is precise and quick. In
certain situations, the spread-and-cut technique with scissors is
permissible. It must be recognized, however, that using the scissors
for spreading and cutting is usually slow and traumatic. It is most
effective in dissecting out neurovascular structures where heavy
scarring is present, and in finding the digital neurovascular bundles
in the hand and foot.

Even if a tourniquet is in place, obtain hemostasis
layer by layer as the dissection proceeds. Isolate small vessels, clamp
with the tip of a forceps, and coagulate. Ligate larger vessels with an
appropriate-size suture. Major arteries and veins in the proximal
portions of the limb generally require double ligature, usually with a
suture ligature in the arteries, using appropriate-size, nonabsorbable
suture material. In the subcutaneous fat, it is sometimes quicker

to
control hemorrhage with light pressure from a sponge or laparotomy tape
and then touch the bleeding points with the electrocautery.

Handle tissues with toothed forceps rather than with
clamps. Be careful not to crush the tissue with the forceps; instead,
use only one tine of the forceps to retract the tissue (Fig. 5.13A).
During suturing, for example, rather than pinching the tissue, it is
better to pass the needle between the tines of the forceps, which are
used to support the tissues (Fig. 5.13B). This technique avoids skin trauma and places the forceps in an ideal position to grasp the end of the suture needle.

For the most part, retraction is used more than
necessary. Do not use it unless you have to. Do not repeatedly handle
tendons or neurovascular bundles. When necessary, place neurovascular
bundles in an appropriate-size Penrose drain loop, which is then used
for gentle retraction. Surgical exposures that exploit the intervals
between muscles are less traumatic than those that split muscles.
Minimize wound exposure to limit contamination and keep tissues moist.
Cover the portions of the wound not in the active surgical field with
saline-moistened sponges. In some instances, particularly in prolonged
procedures where a portion of the wound is not being used, it may be
appropriate to use temporary retaining sutures to hold the tissues
approximated, or staples in the skin. When a second wound is necessary,
such in as bone-grafting procedures, close the ancillary incisions as
soon as possible rather than leaving the wound open until you close the
main wound.

After prolonged surgery, irrigate and debride the wound
as in an open fracture before closure. Excise all damaged and nonviable
muscle. Copiously irrigate with sterile saline using a mechanical
pulsatile lavage-type irrigator.

When handling bone, preserve its vascular supply and
avoid exposing it to excessive heat, which is necrogenic. To preserve
vascular supply, expose only the portion of the bone absolutely
essential to the operation. In the mid diaphysis, the periosteum and
contiguous muscle envelope supply little blood to the cortex;
therefore, subperiosteal dissection is permissible. Preserve the
nutrient artery, perforating vessels, and ligament and tendon
insertions, if possible. Bone fragments with only minimal muscle
attachments are probably devascularized, but if they are anatomically
and securely fixed they may become revascularized.

Necrosis of bone during orthopaedic procedures usually
results from overheating of the bone by cutting and drilling
instruments, especially if they are dull and run at excessive speeds.
Keep all cutting and drilling tools sharp, and cool them with saline
during use. Replace drill points and saw blades frequently. Sharp hand
instruments are essential for precise, skillful, and rapid carpentry of
bone. Avoid stress-risers in bone, which may later lead to pathologic
fracture. Holes or windows in bone, particularly in the mid diaphysis,
are significant stress-risers. Holes smaller than 5 mm in diameter
present few problems, but holes more than 10 mm in diameter, or more
than 30% of the diameter of the bone, lower the strength of bone,
particularly in torsion. Make windows as smooth and round as possible.
Terminate cuts in bone at a drill hole to dissipate the stress-riser
effect.

Hemostasis in bone, particularly cancellous bone, can be
a problem. We prefer bone wax for hemostasis. Soften the wax by
kneading it, and apply it to the bleeding area with the finger
protected by a laparotomy tape. Remove all excess wax.

Because orthopaedic surgery frequently leaves large,
bleeding bone surfaces, suction-drainage is frequently utilized,
although some authors question the necessity of routine drainage (14,30,82,124).
Many drains and methods are available. Take care when placing suction
drains directly on raw, bleeding bone surfaces or in intramedullary
canals to avoid exsanguination. Pass the trocar through the soft
tissues at an angle. This technique may better allow the drainage
tract, which exits the various fascial barriers at separate locations,
to seal. It prevents the development of a persistent draining tract.
Direct connection to wall suction is generally contraindicated because
of the risk of excessive bleeding. Commercially available,
self-activated suction reservoirs are safest. On occasion, it may be
prudent to delay activation of suction until several hours after the
completion of surgery to allow formation of a clot on bone surfaces.

Inadvertent suturing of drains is easily preventable. After inserting and cutting the drain at the appropriate length (Fig. 5.14A), pull the drain back into the wound so that the cut end remains visible during wound closure (Fig. 5.14B). Close the entire wound or fascia with the exception of the part nearest the exposed cut end of the drain (Fig. 5.14C),
then advance the drain to the premarked point, making sure that the
drain is free. Then close the remaining wound. If a drain is
inadvertently sewn in, postoperative removal may be possible; attach a
5-pound weight to break the offending suture. Inspect all drains upon
removal to ensure that breakage has not occurred.

To avoid accidental removal of drains when applying
dressings and moving the patient from the operating table, suture the
drain to the skin or carefully tape it to the extremity. In addition to
providing egress for blood and serum, drains provide a route for
organisms to enter the wound. Remove drains as soon as bleeding and
drainage from the wound have ceased, in most cases by 48 hours after
surgery. To avoid contaminating the wound, do not irrigate plugged
drains. Use large enough drains to prevent plugging by clots.

Minimize the risk of infection by routine irrigation of
wounds before closure. In small wounds for which exposure time has been
short, bulb or syringe-type irrigation is adequate. When wounds have
been exposed for more than 1 hour and involve large surface areas,
copious irrigation with a mechanical pulsatile lavage irrigator is
recommended. The addition of antibiotics or sterile castile soap to the
irrigation solution may be helpful in removing surface bacteria (7,34).
Other authors have reported detrimental effects of aggressive pulsatile
lavage on the soft tissues and early fracture healing (33,89).

Wound closures must be anatomic, atraumatic, and
generally watertight. Use the smallest possible suture that provides
adequate strength. In orthopaedics, running sutures for closure are
generally contraindicated, because use of the limb may result in
failure of these sutures and wound dehiscence. Interrupted sutures
provide a stronger closure and allow fine adjustment of tension to
avoid tissue necrosis.

We use nonabsorbable, synthetic, braided sutures, size 0
or larger, for the repair of ligaments, tendon insertions (except in
the hand and foot and in children, where smaller or different types of
sutures may be indicated), fascia, and fibrous joint capsules. Braided
sutures are easier to handle and are less likely to slip than
monofilament. Use monofilament sutures when the risk of infection is
high, because they are associated with a lower rate of infection than
braided sutures.

In a typical orthopaedic closure, such as a lateral hip wound, we use a size 0 polyglactin suture for repair of

the quadriceps origin using figure-eight sutures. Figure-eight sutures
are helpful when tension is high or sutures tend to pull through the
tissues. Close the deep fascia of the thigh with 0 or 2-0 interrupted
sutures. Close the subcutaneous tissues with inverted, interrupted, 3-0
polyglactin sutures. When cosmetic issues are not of great concern and
speed is important, we close the skin with staples. We generally remove
staples 7 to 14 days postoperatively and replace them with skin tapes.
Interrupted sutures, preferably using a monofilament synthetic,
nonabsorbable material, are an alternative to staples. Avoid
strangulation of the subdermal vascular plexus by approximating the
skin edges without tension.

We do not recommend the use of retention sutures in
extremity wounds. Place sutures at right angles to the skin and 3–4 mm
from the edge. Simple, interrupted sutures are best. We avoid mattress
sutures, if possible, because they devascularize skin edges more than
simple sutures. The suture described by Allgöwer et al. is useful where
the viability of the skin is marginal (Fig. 5.15).
The subcuticular stitch is placed on the most precarious side of the
wound. Use Gillie’s suture on the corners of flaps. For most skin
closures, we prefer a running subcuticular suture of either 3-0 or 4-0
absorbable polyglactin, and in some cases nylon or proline, which is
later removed. Augment this closure with skin tapes placed so that
there is no tension. When significant postoperative swelling is
expected, do not use skin tapes. Avoid benzoin adhesive under skin
tapes because of the risk of allergic reaction.

For surgery of the extremities, we use a supportive
dressing that we call a Robert Jones dressing. Place a sterile,
nonadhesive dressing on the wound. Do not use nonabsorbent dressings,
which do not allow passage of blood and serum, because accumulation of
blood and serum around the incision can cause inflammation. We prefer
gauze impregnated with 3% bismuth tribromophenate (Xeroform) in a
petrolatum blend, with some of the petrolatum scraped off. Over the
gauze, place sterile gauze sponges followed by abdominal pads,
depending on the amount of postoperative blood and fluid expected from
the wound. Encase the entire extremity in bulk, sterile cotton that is
rolled to produce a snug dressing approximately 2–3 inches thick.

Overwrap with 4- or 6-inch wide cast padding followed by
plaster splints to maintain the limb in the desired position. Finally,
overwrap with a bias-cut stockinet. This dressing removes fluids from
the operative site by capillary action. It provides firm support to the
limb to limit swelling, yet there is ample volume to permit swelling of the limb without pressure or neurovascular compromise. The outer hard dressing positions the limb appropriately.

A Robert Jones dressing cannot be used for the proximal
thigh, hip, trunk, or shoulder. In these locations, hold the gauze
sponges and abdominal pads in place with tape or a burn stocking. Use
tape with care in orthopaedics, because considerable postoperative
swelling often occurs. Strong adhesive tape, such as paper tape,
applied tightly may shear the skin and cause blisters. Dress patients
who have a history of tape sensitivity with hypoallergenic tape or no
tape at all. An elastic bandage (Ace-wrap) applied in spica fashion
around hip incisions holds the dressing in place and also provides
gentle compression.

It is important not to place splints against rubberized
pillows, as the heat generated as the plaster sets may be severe enough
to cause a superficial skin burn. Splints should initially remain
uncovered and elevated on cloth blankets or towels until the heat is
dispersed.

Immediately after the conclusion of the procedure, the
surgical team can elevate the limb, position any necessary traction
devices, or reapply thromboembolic stockings or sequential compression
devices. Delay can be minimized if the surgical team performs these
tasks rather than waiting for written postoperative orders to be
followed. Additionally, the surgeon can then be sure that the
appropriate devices and position are used.

The development of an effective vaccine has made
hepatitis B (HBV) a preventable disease. Because of the high risk of
percutaneous injury, all operating room personnel should receive
hepatitis B vaccine. HBV is much more contagious than other viruses;
the risk of transmission of infection has been estimated to be 30%
following a single percutaneous exposure to blood from a patient whose
HBV disease is in the most infectious period (136).

Development of an effective vaccine against hepatitis B
has effected a dramatic decrease in the transmission of HBV to health
care workers through blood exposure. In 1993, an estimated 1,450 health
care workers became infected with HBV though exposure to blood and body
fluids, a 90% decrease from the number infected in 1985. Between 5% and
10% of those infected with HBV develop chronic hepatitis and are at
risk for developing cirrhosis and hepatocellular carcinoma. An
estimated 100 to 200 health care workers have died annually during the
1990s as a result of complications related to chronic HBV infection (25).
Among the orthopaedic surgeons surveyed at the 1991 meeting of the
American Academy of Orthopaedic Surgeons, 67% had received the
hepatitis B vaccination. The incidence of vaccination was inversely
proportional to the age of the surgeon. Ninety percent of surgeons
between 20 and 29 years old had been vaccinated, while only 35% of
surgeons 60 years or older had been vaccinated. Thirteen percent of
individuals showed evidence of infection with HBV and less than 1%
showed infection with hepatitis C. The prevalence of both infections
increased with age. Only 3% of those in their third decade of life were
infected with HBV, while 27% of surgeons 60 years or older showed
serologic evidence of HBV infection (133).

Antibodies to HBV decline with time after vaccination. Up to 60% of those vaccinated lose detectable antibodies over 12 year (25). Despite declining antibody levels, vaccine-induced immunity continues to protect against clinical HBV disease (59).
Further periodic serologic testing is not currently recommended once
adequate antibody response has been confirmed following primary
vaccination (25).

Hepatitis C (HCV), a serious health threat affecting a
large percentage of the population, is a potential risk for practicing
orthopaedic surgeons since no effective vaccine exists. The risk of
infection from needle sticks in HCV is intermediate between that of HIV
and HBV (103). The risk to health care workers from a random needle stick has been estimated to be about 0.1% (58).
Several studies have reported that the risk of seroconversion in health
care workers sustaining a percutaneous exposure to blood from
anti-HCV-positive patients ranges from 0% to 6% (41,77,81).
There appears to be a higher risk from hollow-bore needle sticks than
from the more common suture needle sticks or the other sharp objects
surgeons are exposed to. In one study, four seroconversions were seen
following 331 hollow-bore needle sticks, while no seroconversions were
reported following 105 injuries with suture needles or other sharp
objects (118).

It is recommended that health care workers exposed to
hepatitis C be tested after exposure and again 6–9 months later to
detect hepatitis C antibodies (48). If hepatitis C infection is diagnosed, liver function studies should be performed to evaluate for chronic hepatitis.

In the past, treatment with immune globulin was
recommended following exposure to non-A, non-B hepatitis (now known as
hepatitis C). The immune globulin, which came from pooled plasma (some
from donors infected with HCV), was felt to confer passive immunity.
Since 1992, however, patients who are hepatitis C positive have been
excluded as plasma donors. Current data do not support the use of
immune globulin for prophylaxis against hepatitis C.

Alpha interferon has been shown to be effective in the
short term in the treatment of chronic HCV infection. Treatment is
recommended for patients who are at greatest risk of progression to
end-stage cirrhosis. This group includes patients with a persistently
elevated alanine aminotransferase, presence of HCV RNA in the blood,
and a liver biopsy showing either portal or bridging fibrosis and at
least a moderate degree of inflammation and necrosis (103). Combination of the antiviral medication ribavirin with alpha interferon has shown promise in early studies (121).

The risk of HIV transmission from an infected patient to
an orthopaedic surgeon is unknown. While the risk of seroconversion
after a single percutaneous exposure may be low, great concern remains
about the cumulative risk to orthopaedic surgeons, who often sustain
numerous percutaneous injuries over the course of a lifetime. The
cumulative risk has been estimated to be as high as l% to 4% (160).

While no one knows the exact risk, this figure may

represent an overestimate for several reasons. The risk of HIV
transmission is affected by the degree of viremia in the patient, the
volume of the exposure, and the seroprevalence in the patient
population, which varies greatly by geographical region. An estimated
5% to 10% of acute trauma patients in certain urban areas may be HIV
positive (88).
It is believed that the greatest risk of transmission is from a
percutaneous injury, and that aerosolized particles, mucous membrane
exposure, and exposure to intact skin present a low risk of disease
transmission. Percutaneous injury with a hollow-bore needle is believed
more likely to result in HIV transmission than injury by a solid suture
needle, which is more commonly the experience of orthopaedic surgeons (46).

Virus transmission has not been documented with a
solid-core suture needle injury. Needle type, size, and depth of
penetration have been shown to be independent predictors for the volume
of blood transferred in a percutaneous needle stick. The volume of
blood transmitted is reduced by at least 50% when the needle passes
through a glove made of any kind of material (94).
The probability of transmission of infections may be more associated
with the patient’s viral titer than with the amount of the inoculum (114).
Prospective studies of health care workers have estimated that the
average risk of HIV transmission after a percutaneous exposure to
HIV-infected blood is approximately 0.3% (95% confidence interval, 0.2%
to 0.5%) (15).

As of June 1997, the Centers for Disease Control and
Prevention had received 52 reports of documented U.S. health care
workers who had seroconversion following occupational HIV exposure.
Possible occupational HIV transmission has been reported in 114 cases
in which the health care worker had no other known risk factor but
there was no specific documented exposure (26).
A seroprevalence survey involving 48% of the orthopaedic surgeons
attending the 1991 annual meeting of the American Academy of
Orthopaedic Surgeons found only two HIV-positive individuals (0.06%),
and both of these surgeons reported additional nonoccupational risk
factors (23).

A brief window of time exists after primary HIV
infection before systemic infection occurs. During this time,
postexposure antiretroviral intervention may modify viral replication.
The U.S. Public Health Service has established recommendations for
postexposure prophylaxis based on the risk of infection following the
exposure and the infectivity of the exposure source (26) (Fig. 5.16).
These recommendations are likely to continue to evolve as new
retroviral agents or combination of agents are introduced and as HIV
strains develop drug resistance. The risks of toxicity and side effects
from prophylaxis will need to be continually weighed against the
relatively low risk of disease transmission following an occupational
exposure.

In one study, 74% of surgeons’ documented exposures to
blood during surgery were potentially preventable by the use of
additional barrier precautions, such as face shields and
fluid-resistant gowns (111). Although there
have been no documented cases of transmission, the possibility has been
raised that HIV could be transmitted via aerosolized particles produced
by power tools (70). Use face shields to prevent this kind of contamination (76)
and splash shields to minimize the spread of the aerosolized fluids
from mechanical pulsatile lavage. Double gloving, initially popularized
in total joint arthroplasty as a way of minimizing the risk of the
surgeon’s contaminating the patient (95), has
become important in protecting the surgeon. Latex glove perforation
occurs frequently. The use of double gloves has been shown to be
effective in minimizing the risk of perforation. Double gloving may
result in a 60% to 80% decrease in inner glove perforation and visible
blood contamination (49). Some authorities
recommend inspecting and routinely changing latex gloves at least every
2 hours during long-duration procedures (87,126). One author has recommended that gloves be changed at least every 25 minutes (114). Cloth, Kevlar, and stainless-steel-reinforced gloves provide additional protection from perforation (63,87,126,145).
Despite the use of these reinforced protective gloves, perforation of
the inner gloves nevertheless occurs and may go unrecognized. Fluid
sensors have been developed to alert surgeons when a glove has been
penetrated.

Use fluid-impervious gowns during surgeries in which the
gown may become saturated with blood or fluid. The use of a
self-contained air exchange system may also offer protection, but the
benefits it confers may be outweighed by communication difficulties it
causes that could lead to accidental injury (28).
Alternatively, an impervious urology apron worn under the surgical gown
effectively prevents contamination of the trunk and lower extremities (49).
Knee-length rubber boots or impervious shoe covers are recommended for
cases in which the potential for blood loss is significant, or during
arthroscopy.

The American Academy of Orthopaedic Surgeons (AAOS) has
recommended changing surgical methods to reduce the risk of injury: Be
aware and cautious, use pop-off needles, avoid having more than one
person suture at a time, announce the passage of sharp instruments and
pass them in a kidney basin or other device. Take care to avoid digital
palpation of fracture sites or sharp bone surfaces. Cover pins and
wires with protective caps. Periodically inspect gloves and gowns (4).

In the event of a percutaneous exposure, the AAOS recommends the following procedure (4):

Prevention of thromboembolic disease is a critical issue
in orthopaedic surgery. Recent studies have highlighted the
pervasiveness of this problem among several orthopaedic patient
populations (50,130,158).
Without prophylaxis, a deep venous thrombosis may occur in 40% to 60%
of patients undergoing total hip or knee arthroplasty. Proximal deep
venous thrombosis may occur in 15% to 20%, and a fatal pulmonary
embolism may occur in 0.5% to 2% (85). Risk
factors that have been identified for thromboembolic disease include
age (becoming clinically important by age 40 and increasing
thereafter); prolonged immobility or paralysis; history of prior
thromboembolism; cancer; major surgery (particularly operations on the
pelvis and lower extremities); obesity; varicose veins; congestive
heart failure; myocardial infarction; stroke; fractures of pelvis, hip,
or leg; and possibly high-dose estrogen use (29).

Numerous methods of prophylaxis have been investigated,
and authorities recommend both mechanical and pharmacologic methods.
Intraoperative anesthetic techniques including hypotensive and epidural
anesthesia have been shown to reduce the risk of thromboembolism (86,134).
Mechanical methods include use of compression stockings and various
pneumatic compression devices. Pharmacologic methods include dextran,
aspirin, warfarin, heparin, and low-molecular-weight heparin.

Diagnosis of thromboembolic complications, most of which
are asymptomatic, remains difficult. Methods for diagnosis of deep
venous thrombosis include impedance plethysmography, fibrinogen I-125
scanning, venography, and duplex ultrasound. Diagnostic methods for
pulmonary embolism are ventilation-perfusion scanning and pulmonary
angiography. There is controversy over the ideal diagnostic testing
modality because of variation in sensitivity and specificity of the
different tests. They also vary in their ability to image different
parts of the venous systems, and in the invasive risk they pose to the
patient.

In cases where deep venous thrombosis is diagnosed,
controversy also exists over whether all thrombi should be treated,
what method of treatment should be used, and how long treatment should
last. Low-molecular-weight heparin, which does not require laboratory
monitoring, is increasingly the treatment of choice in the outpatient
management of deep venous thrombosis (155). The
numerous investigations and recommendations on this important subject
are beyond the scope of this chapter. While many therapeutic methods
have been shown to reduce the risk of thromboembolism, no single method
is completely effective or applicable to all situations. Metaanalysis
of recent randomized clinical trials has shown low-molecular-weight
heparin to be superior to warfarin in prevention of deep venous
thrombosis, but its use is associated with a greater number of minor
bleeding complications (110). Each surgeon must
assess the varying risk that thromboembolism presents to each
individual patient, selecting the prophylactic method that appears to
provide the greatest risk reduction when balanced against any potential
risk of the treatment itself.