Week 15 Handout Flipped Classrooms: Total Hip Arthroplasty (THA)

Question 1

What is Total Hip Arthroplasty (THA)?

Answer 1

Surgical replacement of the hip joint.

Question 2

What materials are used in Total Hip Arthroplasty?

Answer 2

Early prostheses: Stainless steel. Modern: Cobalt/chromium or titanium alloys (stronger, fatigue-resistant).

Question 3

What are the goals of Total Hip Arthroplasty?

Answer 3

Relieve pain, improve mobility, restore joint stability.

Question 4

What are the indications for Total Hip Arthroplasty?

Answer 4

Osteoarthritis (most common), hip fractures, rheumatoid arthritis (RA) or other autoimmune conditions.

Question 5

What is the typical patient population for Total Hip Arthroplasty?

Answer 5

Typically elderly or obese, with multiple comorbidities.

Question 6

What are the surgical approaches for Total Hip Arthroplasty?

Answer 6

Posterior: Most common; larger incision, better visualization. Anterior: Muscle-sparing, minimally invasive, faster recovery, more technical. Anterolateral (Watson-Jones): Less common; may affect abductors.

Question 7

What is the positioning for the posterior approach in Total Hip Arthroplasty?

Answer 7

Lateral decubitus.

Question 8

What is the positioning for the anterior approach in Total Hip Arthroplasty?

Answer 8

Supine on traction table.

Question 9

What are the steps in Total Hip Arthroplasty?

Answer 9

1. Skin incision 2. Removal of the femoral head 3. Acetabular preparation (reaming to shape socket) 4. Trial component testing and final prosthesis placement 5. Wound closure.

Question 10

What are clinical notes regarding Total Hip Arthroplasty?

Answer 10

Most common hip replacement method. Can be performed via posterior, anterior, or lateral approach. Requires careful positioning and hemodynamic monitoring, especially if using cement.

Question 11

What are the indications for Revision Arthroplasty?

Answer 11

Previous implant failure, infection, loosening, or periprosthetic fracture.

Question 12

What are key differences in Revision Arthroplasty compared to primary THA?

Answer 12

More technically complex than primary THA. Increased blood loss risk → prepare with neuraxial anesthesia (↓ bleeding), autologous donation, intra-op blood salvage (cell saver), pre-op hematologic optimization: iron, vitamin B12, vitamin K, erythropoietin.

Question 13

What are the features of Hip Resurfacing Arthroplasty?

Answer 13

Preserves more native bone, particularly in the femoral neck. Uses metal-on-metal (MoM) implants.

Question 14

What is the preferred approach for Hip Resurfacing Arthroplasty?

Answer 14

Posterior.

Question 15

What are the risks associated with Hip Resurfacing Arthroplasty?

Answer 15

Higher revision rate, metal hypersensitivity, femoral neck fracture (especially in women), cobalt/chromium toxicity. Monitor serum metal levels. Risk of local tissue damage from metal debris (ALTR = adverse local tissue reaction).

Question 16

What is the technique used in Minimally Invasive Arthroplasty?

Answer 16

Utilizes small incisions and computer-assisted surgery (CAS).

Question 17

What are the potential advantages of Minimally Invasive Arthroplasty?

Answer 17

↓ postoperative pain, faster recovery time, improved cosmesis.

Question 18

Is there clear superiority in outcomes for Minimally Invasive Arthroplasty over conventional techniques?

Answer 18

No clear superiority in outcomes.

Question 19

What preoperative considerations should be evaluated?

Answer 19

Comorbidities: Evaluate for OA, RA, obesity, CAD, COPD. Functional status: Ambulation, cardiac/pain limitations. RA concerns: Cervical spine & airway instability → consider awake fiberoptic. Labs & Meds: CBC, BMP, coagulation panel, anticoagulants. Positioning constraints: May impact spinal approach feasibility. May need lateral spinal approach. Communication: set expectations.

Question 20

What is the preferred anesthesia technique?

Answer 20

Neuraxial anesthesia (spinal or epidural ± sedation)

It decreases mortality, infection, thromboembolism, and acute kidney injury (AKI).

Question 21

When is general anesthesia needed?

Answer 21

General anesthesia may be needed in patients with contraindications to neuraxial.

Question 22

What is combined anesthesia?

Answer 22

Combined anesthesia is spinal or epidural with light general anesthesia for longer cases or patient comfort.

Question 23

What is the benefit of neuraxial opioids?

Answer 23

Neuraxial opioids (morphine/hydromorphone) provide extended post-operative pain control.

Question 24

What do ASRA guidelines recommend regarding neuraxial placement?

Answer 24

ASRA guidelines recommend carefully timing neuraxial placement with anticoagulant administration.

Question 25

What caution is advised for patients with aortic stenosis?

Answer 25

Caution is advised with spinal anesthesia in patients with aortic stenosis.

Question 26

What is Bone Cement Implantation Syndrome (BCIS)?

Answer 26

BCIS occurs during methyl methacrylate cement use and involves emboli, histamine release, complement activation, and endocannabinoid vasodilation.

Question 27

What are the symptoms of BCIS?

Answer 27

Symptoms include sudden ↓ ETCO₂, hypoxia, hypotension, arrhythmias, loss of consciousness, and cardiac arrest.

Question 28

What are the risks associated with BCIS?

Answer 28

Risks include rheumatoid arthritis, ASA III+, long-stem implants, fractures, and surgical technique.

Question 29

How is BCIS managed?

Answer 29

Management includes treating like right-sided heart failure: 100% FiO₂, IV fluids, alpha-agonists (phenylephrine), and monitoring closely post-cement.

Question 30

What triggers Fat Embolism Syndrome (FES)?

Answer 30

FES is common after long bone trauma, but can also be triggered by CPR, lipid infusion, and liposuction.

Question 31

What are the pathophysiology theories of FES?

Answer 31

Theories include mechanical (fat globules from bone marrow enter torn vessels) and metabolic (circulating free fatty acids aggregate and become toxic).

Question 32

What are the physiologic effects of FES?

Answer 32

Fat globules and inflammatory mediators damage capillaries, especially in the lungs (ARDS, hypoxemia) and brain (cerebral edema, neurologic symptoms).

Question 33

What is the classic triad for diagnosing FES?

Answer 33

The classic triad includes dyspnea, confusion, and petechiae.

Question 34

What are the ocular signs of FES?

Answer 34

Ocular signs include retinal fat globules and fat in urine or sputum.

Question 35

What laboratory findings may indicate FES?

Answer 35

Thrombocytopenia, increased clotting time, and possibly increased serum lipase.

Question 36

What are the management strategies for FES?

Answer 36

Management includes early fracture stabilization and supportive care with high flow O2 or PEEP/CPAP, vasopressors, and possibly pulmonary vasodilators.

Question 37

What causes DVT/PE?

Answer 37

DVT/PE is caused by venous stasis and a hypercoagulable state from inflammation.

Question 38

What are the risk factors for DVT/PE?

Answer 38

Risk factors include age >60, obesity, immobilization >4 days, surgery >30 min, tourniquet use, and lower extremity fractures.

Question 39

What are high-risk surgeries for DVT/PE?

Answer 39

High-risk surgeries include hip/knee replacements and major lower extremity trauma.

Question 40

What are the DVT rates without prophylaxis?

Answer 40

Without prophylaxis, DVT rates can be 40–80%.

Question 41

What is the incidence of PE post-hip surgery?

Answer 41

PE incidence post-hip surgery can be up to 20%, with fatal PE rates of 1–3%.

Question 42

What are the prevention strategies for DVT/PE?

Answer 42

Prevention includes mechanical methods (SCDs, IPCs) and pharmacologic methods (low dose UFH, LMWH, warfarin, DOACs).

Question 43

What is the role of tranexamic acid (TXA) in DVT/PE prevention?

Answer 43

TXA is used to reduce bleeding.

Question 44

What pre-operative measures should be taken for hemorrhage?

Answer 44

Ensure blood availability and use large-bore IVs and warming devices.

Question 45

What are other complications to consider?

Answer 45

Other complications include nerve/pressure injury, multimodal pain control, respiratory depression, infection, and airway difficulty.

Question 46

What are the key anesthesia priorities?

Answer 46

Key priorities include preferring neuraxial anesthesia, knowing BCIS & FES, individualizing care, using multimodal analgesia, prophylaxis for thromboembolism and infection, and intra-operative vigilance.

Question 47

During THA using methyl methacrylate cement, what is the first sign of bone cement implantation syndrome (BCIS) under general anesthesia? A. Hypotension B. Sudden bradycardia C. Decreased end-tidal CO₂ D. Desaturation on pulse oximetry

Answer 47

Correct Answer: C Rationale: An abrupt decrease in end-tidal CO₂ is often the earliest indication of clinically significant BCIS under general anesthesia due to acute pulmonary embolization or increased dead space ventilation (Elisha et al., 2023, p. 1035).

Question 48

Which of the following intraoperative interventions is MOST appropriate during cementing in a patient at risk for BCIS? A. Administer IV heparin to prevent clotting B. Increase FiO₂ to 100% and ensure full IV fluid bags C. Turn patient supine to improve cardiac preload D. Start a nitroglycerin infusion to reduce afterload

Answer 48

Correct Answer: B Rationale: Administering 100% FiO₂ increases oxygen reserve and improves oxygenation in case of embolic events. Having IV fluids ready and maintaining normovolemia supports cardiac preload and blood pressure, minimizing the hemodynamic impact of BCIS. These interventions are evidence-based strategies used to mitigate the risk and severity of BCIS (Elisha et al., 2023, p. 1035).

Question 49

What is the most common indication for Total Hip Arthroplasty in the United States? A. Rheumatoid arthritis B. Hip fracture due to trauma C. Degenerative joint disease (osteoarthritis) D. Avascular necrosis of the femoral head

Answer 49

Correct Answer: C Rationale: Most patients undergoing THA have osteoarthritis (degenerative joint disease). Osteoarthritis is a degenerative disease affecting the articular surface of joints (commonly the hips and knees). The etiology of osteoarthritis appears to involve repetitive joint trauma (Butterworth et al., 2022, p. 813).

Question 50

Which statement is true regarding the anterior approach to THA compared to the posterior approach? A. It requires a larger incision with more muscle dissection B. It results in longer hospital stays C. It has increased dislocation risk and bleeding D. It is muscle-sparing and allows faster recovery

Answer 50

Correct Answer: D Rationale: The anterior approach to total hip arthroplasty is considered minimally invasive as it avoids cutting major muscles, unlike the posterior approach. By preserving key musculature, patients often experience reduced postoperative pain, faster rehabilitation, and shorter hospital stays. Although technically demanding and associated with a steeper learning curve, the anterior approach is increasingly favored for suitable candidates due to its functional benefits (Elisha et al., 2023, p. 1035).

Question 51

Which of the following is a classic triad of symptoms for fat embolism syndrome (FES)? A. Fever, chills, petechiae B. Chest pain, dyspnea, hemoptysis C. Hypoxemia, altered mental status, and a petechial rash. D. Hypotension, headache, jaundice

Answer 51

Answer: C Rationale: FES typically presents with a triad involving respiratory, neurologic, and dermatologic symptoms. Hypoxemia occurs due to fat globules obstructing the pulmonary microvasculature. Neurologic symptoms such as confusion or altered mental status result from cerebral embolization or hypoxia. A petechial rash, especially on the upper body, results from dermal capillary occlusion. (Elisha et al., 2023, p. 1045).

Question 52

Which complication requires padding and careful positioning in the lateral decubitus position during THA? A. Pressure injuries and nerve damage B. Hemorrhage C. BCIS D. PONV

Answer 52

Answer: A Rationale: The lateral decubitus position, commonly used in total hip arthroplasty, places patients at increased risk for pressure-related injuries and peripheral nerve damage due to prolonged compression. Improper positioning or inadequate padding can compress nerves such as the brachial plexus, peroneal, or sciatic nerves, potentially leading to postoperative neuropathies. Pressure ulcers can also develop over bony prominences (Elisha et al., 2023, p. 1030).