Comprehensive Study Notes on Total Joint Replacement (TJA)

Epidemiology and Overview of Total Joint Replacement (TJA)

• Total joint replacement (TJA), also referred to as total joint arthroplasty, is most commonly associated with the joints of the hip and the knee but may also include any and all joints within the body. Other common areas include the shoulder, elbow, ankle, and wrist.
• Definition: This is a surgical procedure designed to repair articulating surfaces within a synovial joint. A new smooth surface is restored to the joint.
• The typical lifespan for a joint replacement is approximately $10$ to $15$ years.
• Statistics and Trends:     - In 2020, orthopedic surgeons performed approximately $800,000$ total knee arthroplasties (TKAs) and $2$ million total hip arthroplasties (THAs).     - Projections indicate that TKAs are expected to increase by $143 \%$ by 2050 compared to 2012 data.     - Literature shows a $24.4 \%$ increase in THAs from 2019 to 2020.
• Economic and Care Factors:     - Over the past decade, there has been a reduction in cost and an improvement in the quality and efficiency of care for TKA and THA patients.     - These improvements are attributed to the Bundled Payments for Care Improvement (BPCI) program created by the Centers for Medicare and Medicaid Services (CMS) and other insurance-driven initiatives.

Pathophysiology and Clinical Manifestations

• Osteoarthritis (OA) is the leading clinical indication for Total Joint Arthroplasty.
• Anatomical Changes in OA:     - Joint cartilage consists of a matrix of proteoglycans and collagen.     - In OA, there is a decrease in proteoglycans, which are responsible for the management of fluid within the joints. This leads to a loss of cartilage strength and functionality.     - Normal cartilage is bluish-white in color. With OA, it slowly changes to a translucent color, then opaque, and finally yellow-brown in appearance.
• Disease Progression:     - Erosion of cartilage and bone leads to a reduction and narrowing of the joint space.     - Production of bone spurs, known as osteophytes, occurs.     - The disease develops fissures, pitting, and ulcerations, while the cartilage continues to thin.
• Inflammatory Response:     - The body produces cytokines (enzymes) such as interleukin-1, which enhance the deterioration.     - The normal body compensatory mechanisms cannot overcome this rapid degeneration.
• Final Clinical Outcomes: Joint destruction, dysfunction, and deformity, which lead to immobility, pain, muscle spasm, and localized inflammation. Joint replacement involves the removal of the damaged area of the bones with a replacement prosthesis (partial or complete).

Interprofessional Management and Diagnosis

• Diagnosis Criteria: Determining the need for TJA is based on deformity, tissue destruction, and loss of function of a specific joint.
• Common indicators include joint changes, stiffness, pain that limits normal activities, and associated muscle atrophy.
• Diagnostic Studies: The need for replacement is confirmed through radiographical studies such as X-rays and MRI that reveal structure and joint pathology.
• Initial Medical Management (Conservative Approach):     - Focuses on weight management and activity modification.     - Use of nonsteroidal therapy (NSAIDs).     - Use of joint supplements such as glucosamine and chondroitin.
• Comprehensive Preoperative Physical Examination for TJA:     1. Assessment of range of motion (ROM) of the joint, noting any joint contractures.     2. Presence of crepitus and/or pain (for TKA, notation in the patellofemoral, medial, or lateral joint) on active or passive flexion/extension.     3. Careful examination of ligaments for stability or contractures and notation of degree (mostly for TKA).     4. Spine and hip examination.     5. Neuromuscular examination with notation of strength and tone.     6. Gait assessment.     7. Pulse assessment.     8. Skin assessment.

Contraindications and Surgical Indications

• Contraindications for TKA:     - Active infection.     - Neurological conditions affecting neurovascular function to the affected lower extremity.     - Chronic lower extremity ischemia.     - Skeletal immaturity.
• Contraindications for THA:     - Preexisting significant medical problems (myocardial infarction, unstable angina, heart failure, severe anemia).     - Skeletal immaturity.     - Tetraplegia.     - Permanent or irreversible muscle weakness without pain.
• Indications for THA/TKA Surgery (Table 53.6):     - Osteoarthritis: Degenerative wear of articular cartilage and bony cyst formation.     - Rheumatoid arthritis: Destruction of articular cartilage and bony erosions.     - Previous injury or surgery: Abnormal wearing of joint surfaces due to anatomical alignment changes.     - Previous childhood hip disease (THA): Conditions like developmental dysplasia of the hip, Perthes disease, or slipped capital femoral epiphysis (misalignment of femur and hip).     - Avascular necrosis of the femoral head (THA): Death of the femoral head due to trauma (up to $8$ years after event) or alcohol/corticosteroid use.     - Intracapsular fractured neck of femur (THA): Often treated with THA if there is pre-existing arthritis in the fractured hip (vs. hemiarthroplasty).     - Ankylosing spondylitis (THA): Bony ankylosis (loss of movement) of the hip joint.

Surgical Management Techniques

• Surgical approach involves resurfacing the joint and/or complete or partial replacement.
• Component Materials: Most prostheses consist of a cobalt-chrome polished ball with a polyethylene cup or socket (ball and socket).
• Fixation Methods:     - Cemented approach: Uses polymethylmethacrylate cement (glue) to attach the prosthesis to the bone. The cement acts as a filler, providing stable fixation. This is typically used for older patients with poor bone quality or those with a life expectancy of $20$ years or less who are unlikely to require revision surgery.     - Uncemented (Cementless) approach: Secured by placing an anatomically correct hole in the bone. The prosthetic joint is coated with hydroxyapatite, which allows for bone ingrowth into the surface, creating a stable bond. This is used for younger, more active patients, allowing for easier removal if a revision is required later.
• Alternatives and Approaches:     - Joint Resurfacing: For younger patients, shaving the femoral head while preserving the femoral neck and inserting a metal cup and socket. This reduces surgical/recovery time and optimizes outcomes.     - Unicondylar or Partial Knee Replacement: An alternative to TKA where only one compartment is replaced.     - Traditional Surgical Approach: Incision of approximately $20$ to $30\,cm$ with staples or sutures. Longitudinal versus lateral approaches affect muscle damage levels.     - Minimally Invasive Surgical Approach: Incision of approximately $10\,cm$ or less. Advantages include reduction in tissue trauma and faster recovery, though joint visualization is limited.
• Intraoperative Tools: Drains are placed to prevent hematoma and allow for autologous blood transfusion within the first $6$ hours of surgery.

Postoperative Complications

• Immediate Complications: Hypotension, bleeding, and hypovolemia due to excessive blood loss.
• Infection: Potential wound site infection is managed via intraoperative and postoperative asepsis (hand washing, drain cleaning, monitoring temperature and WBC count). Prophylactic antibiotics are protocol until the drain is removed.
• Dislocation and Subluxation: The prosthesis becomes loose or misaligned. Signs include asynchrony in leg length or abnormal rotation of the hip, causing severe pain and inability to bear weight.
• Heterotrophic Ossification (HO): A rare disorder involving the formation of extraskeletal bone in muscle or soft tissue, limiting range of motion. Treated with prophylactic NSAIDs or single-dose external beam radiation.
• Life-Threatening Complications: Deep vein thrombosis (DVT) and potential pulmonary embolism (PE).

Nursing Management: Assessments and Interventions

• Nursing Diagnoses:     - Acute/chronic pain associated with joint destruction.     - Activity intolerance associated with limited physical mobility.     - Risk for infection associated with surgical site complication.
• Preoperative Nursing Assessments:     - Presurgical screening: ECG, metabolic profile, coagulation studies, and complete blood count (CBC).     - Anesthesia risk screening to decrease cardiopulmonary compromise.     - Pain management and assessment of pain tolerance.
• Postoperative Nursing Assessments:     - Vital signs: Monitoring for hypertension/tachycardia/tachypnea (perfusion issues) or hypotension/tachycardia (hypovolemia).     - Temperature: To detect postoperative infection.     - Pain Level: Management is crucial for early mobilization.     - Laboratory assessment: Monitoring hemoglobin and hematocrit for blood loss.     - Neurovascular assessment: Checking the Six Ps (Weak pulses, pallor, paresthesia, paralysis, pulselessness, and pain).     - Wound drainage: Excessive bloody drainage or thick, purulent drainage must be evaluated.
• Postoperative Actions:     - Administer pain medication: Patient-controlled analgesia (PCA) weaning programs ($24-48$ hours) with introduction of opioids and nonsteroidal therapy.     - Wound care: Maintain secure dressing and drain utilizing aseptic technique.     - Mobilization: Early movement from bed to chair within $6$ hours postoperatively.     - DVT Prophylaxis: Antiembolic stockings, sequential compression devices (SCDs), and anticoagulant therapy (often for $4-6$ weeks).     - Continuous Passive Motion (CPM): Gently flexes and extends the knee after TKA, though routine use isn't universally supported by evidence.     - Positioning: Use of abduction pillows for THA to prevent dislocation; strict turning schedules to prevent decubitus ulcers on heels and bony prominences.

Patient Education and Discharge Teaching

• Opioid Precautions: Side effects include constipation, drowsiness, and respiratory depression. Patients must not drink alcohol or operate heavy machinery (cars).
• Anticoagulation Teaching:     - Use of low-molecular-weight heparin (LMWH) subcutaneous injections in the home setting.     - Signs of DVT: Pain, warmth, and tenderness at the site.     - Bleeding precautions: Use electric razors, soft toothbrushes, no flossing, and avoid high-risk activities (e.g., football).     - Diet: If on warfarin, maintain a consistent intake of Vitamin K-rich foods (green vegetables) as they interfere with efficacy.
• Home Management and Safety:     - Exercise: $20$ to $30$ minutes of exercise, two to three times daily.     - THA Restrictions: Maintain hip flexion less than $90^{\circ}$ for approximately $2$ to $3$ months.     - Environmental Modifications: Use a raised toilet seat, pull bars in the bathroom, remove scatter rugs, and wear nonslip socks or shoes.     - Movement: Avoid crossing the leg over the midline to prevent hip abduction and venous stasis.
• Evaluating Care Outcomes: Goals include reduction in pain, restoration of functional outcomes, prevention of hypovolemia, prevention of surgical site infection, and prevention of prosthesis dislocation.

Questions & Discussion

Connection Check 53.7

• Question: Which symptom is an appropriate indication for TJA?
• A. An inability to perform activities of daily living without pain
• B. A desire to participate in contact sports without pain
• C. A knee injury that may restrict aggressive skiing
• D. A hip injury that restricts a prior running routine
• Answer: A. An inability to perform activities of daily living without pain