Preop Considerations

• If fracture is present, possible preop complications include:

» Occult blood loss.

» Dehydration.

» Hypoxia due to fat embolism (triad of dyspnea, confusion, & petechiae usually present within 72 h of fracture).

» Thromboembolism.

• Common coexisting diseases in this usually elderly population.

» Osteoarthritis.

» Rheumatoid arthritis (RA).

– In pts w/ severe RA requiring steroids or methotrexate, get lateral c-spine radiograph to assess for atlantoaxial subluxation & need for fiberoptic intubation.

– For preop steroid use, consider stress-dose steroids; pt may have glucose intolerance, fragile skin, easy bruising.

» Coronary artery disease.

» Cerebral vascular disease.

» COPD.

» Diabetes.

• If pt has severe pulmonary disease, discuss w/ surgeon need for cemented prosthesis (which may increase pulmonary complications).

• Look for coagulopathy.

» Surgery assoc w/ high blood loss potential.

» Correct coagulopathy preop.

» Consider aprotinin for high-risk bleeding cases.

» Consider intraop red cell salvage.

Physical Findings

• Pts w/ arthritis may have limited joint mobility in neck & extremities.

• Most pts (esp elderly) will have limited exercise tolerance because of hip, making cardiopulmonary status more difficult to assess.

Workup

• CBC.

• ABG if pt hypoxic & suspected to have fat embolism.

• Preop EKG to establish risk & baseline.

Choice of Anesthesia

• GA

» Advisable in obese pt or arthritic pt w/ anticipated difficult airway.

» Consider in redo total hip arthroplasty (THA), which is assoc w/ increased blood loss & longer operative times.

» May be combined w/ spinal or epidural.

• Spinal anesthesia

» Consider isobaric local anesthetic to limit cephalad spread & sympathectomy (compared to hyperbaric solution).

» If pt unable to sit, may administer hypobaric solution w/ pt in lateral decub position.

» Can administer intrathecal morphine to provide analgesia for up to 24 h.

• Epidural anesthesia

» Offers benefit of postop analgesia.

» Communicate w/ surgeon regarding timing of postop anticoagulation. Remove epidural catheter prior to initiation of anticoagulant therapy to reduce risk of epidural hematoma.

• Important: Avoid neuraxial blockade in pts receiving preop anticoagulation because of increased risk of epidural hematoma.

• Neuraxial blockade assoc w/ reduction in blood loss by 30-50%.

• Hypotensive or regional anesthesia that lowers MAP to ~55 mmHg effective in reducing blood loss.

» Ensure pt's other organ systems can tolerate this.

» May want to avoid hypotensive technique in pt w/ significant cardiovascular or cerebrovascular disease.

Monitors/Line Placement

• Routine monitors.

• Consider arterial line, which may be useful for close BP monitoring & blood draws.

» BP often drops during cementing & hardware implantation.

• Central line optional

» Consider introducer sheath if pt has poor peripheral veins.

» Consider for pt w/ significant cardiac disease (eg, CHF).

• Adequate peripheral IV access required for fluid resuscitation & blood transfusion.

• Anesthesia usually induced on gurney, especially if pt has significant pain.

• Foley catheter placed after induction.

Intraop Concerns

• Fat embolism syndrome.

» Clinical triad of dyspnea, confusion, petechiae.

» Under GA, can present w/ hypotension, petechiae, hypoxemia.

» Most common during insertion of femoral prosthesis.

» Mgt includes supportive care, oxygen administration, mechanical ventilation, repair of fracture.

• Bone cement implantation syndrome.

» Methylmethacrylate cement implicated as cause, although pressurization of cement into femoral canal, as well as surgical manipulation of femoral canal w/ rasps, etc, may be contributing factors.

» Manifestations include hypoxia, hypotension, dysrhythmias, pulmonary HTN, decreased cardiac output.

» Most common during insertion of femoral prosthesis

» Consider prophylaxis w/ increased FiO₂ & maintenance of adequate volume status.

» Surgeons may place vent in distal femur to decrease intramedullary pressure or perform high-pressure lavage of femoral shaft to remove debris.

» Mgt includes supportive care (eg, increased oxygen, vasopressors or inotropes).

• Pulmonary embolism

» May represent a spectrum of fat embolism or cement implantation syndrome.

» Findings can include hypoxemia & hypotension.

» Mgt includes supportive care.

» See also Critical Event chapter "Pulmonary Embolism."

• Hemorrhage

» Usually visible from operative field, although bleeding into thigh can contribute 500-1,000 ml to EBL.

» Red cell salvage may be useful in minimizing allogeneic blood transfusion.

• Positioning issues

» Pt in lateral decubitus, w/ upper arm suspended.

» Consider axillary roll.

» Keep spine straight, especially c-spine.

» Pad & position pt carefully to minimize chance of peripheral nerve injury.

Intraop Therapies

• Consider controlled hypotension to MAP of 55 mmHg if pt does not have significant cardiovascular or cerebrovascular disease.

Pain

• Moderate to severe.

• Consider intrathecal or epidural morphine. Watch for respiratory depression, esp in elderly pts.

• Consider PCA if pt did not receive epidural or spinal analgesia.

Complications

• Postop hemorrhage usually monitored by following drain output. Some surgeons use postop cell salvage from drain.

• Pts at high risk of DVT & pulmonary embolism. Pts usually receive DVT prophylaxis with low-molecular-weight heparin, & possibly compression stockings or intermittent pneumatic compression device.

Indications

• Osteoarthritis, pathologic fractures of femoral neck, prosthesis failure, trauma.

Procedure

• Total hip arthroplasty refers to replacement of femoral & acetabular components of hip joint.

• Hemi-arthroplasty refers to replacement of only one component.

• Bipolar or unipolar refers to the engineering of the femoral component (bipolar more common because it allows greater range of motion).

• Some prostheses do not require cement & may therefore have reduced chance for hypotension.

• Basic steps of procedure

» Hip is exposed via lateral incision.

» Femoral head is removed.

» Intramedullary canal is reamed.

» Prosthesis is measured & then hammered into place (this is when embolization may occur).

» Acetabular component is placed in pelvis.

Surgical Concerns

• Blood loss

» EBL during hip revisions can be considerable. Consider arranging autologous donation or providing intraop cell salvage.

• Sciatic nerve injury

Typical EBL

• 500-3,000 cc.

• Anticipate higher blood loss for repeat surgery.

Hsiupei Chen, MD
Michael Gropper, MD, PhD