Background

Total Knee Arthroplasty has become one of the most successful and commonly performed orthopedic procedures worldwide. It has provided relief to millions of individuals suffering from debilitating knee arthritis, improving their quality of life and restoring functional mobility. The history of TKA reflects a continuous commitment to innovation, research, and patient-centric care in the field of orthopedic surgery.

The first attempts at knee arthroplasty involved non-anatomical designs and materials like ivory, wood, and rubber. In the 1950s, Sir John Charnley, a British orthopedic surgeon, introduced the concept of low-friction arthroplasty. He pioneered the use of high-density polyethylene as a bearing surface, reducing friction and wear in the joint. The first generation of total knee implants emerged in the 1970s. Designs included hinge-type prostheses that aimed to replicate natural knee movement.

During the 1980s and 1990s, advancements in design and materials significantly improved TKA outcomes. Surgeons shifted towards using cementless fixation for some implants, enhancing implant stability. Improved implant designs aimed to replicate natural knee kinematics, allowing for better range of motion and stability. The introduction of computer-assisted surgery and patient-specific instrumentation enhanced surgical precision. 

In the 2000s, minimally invasive techniques gained popularity in TKA. These approaches aimed to reduce surgical trauma, accelerate recovery, and minimize scarring. Computer navigation systems and robotic-assisted surgery became tools to enhance the accuracy of implant placement. Advances in surgical techniques, perioperative care, and rehabilitation have contributed to shorter hospital stays and faster recovery. Patient-specific implants and personalized approaches based on individual anatomy continue to evolve. 

Indications

• Osteoarthritis: Osteoarthritis is the most common reason for TKA. It involves the progressive breakdown of the cartilage in knee joint, leading to pain, stiffness, and loss of function. 
• Rheumatoid Arthritis: Rheumatoid Arthritis is a autoimmune disorder that affects joints, including the knee. TKA may be recommended when conservative treatments fail to provide relief. 
• Post-Traumatic Arthritis: Severe joint damage and arthritis that develop after a traumatic injury to the knee, such as fractures involving the joint surface or ligament injuries. 
• Other Inflammatory Arthropathies: Inflammatory conditions like lupus or psoriatic arthritis that led to joint destruction and disability. 
• Hemophilic Arthropathy: Individuals with hemophilia may develop hemophilic arthropathy, a condition characterized by bleeding into the joints. 
• Severe Deformity: Advanced joint deformities, such as severe bowing or varus/valgus deformities, that significantly impact joint function and stability. 
• Failed Previous Surgical Procedures: Individuals who have undergone previous knee surgeries (such as arthroscopy or osteotomy) that have not provided sufficient relief or have led to further joint deterioration. 
• Persistent Pain and Functional Limitations: Chronic knee pain and functional limitations that significantly impact daily activities, quality of life, and the ability to perform routine tasks. 
• Failure of Conservative Treatments: TKA is typically considered after conservative measures, such as medications, physical therapy, and joint injections, have failed to adequately control symptoms. 
• Age and Activity Level: While age alone is not a strict criterion, TKA is often recommended for individuals of various age groups who experience significant symptoms and are willing to commit to postoperative rehabilitation. 

Contraindications

• Active Infection: Individuals with active infections, either systemic or localized to the knee joint, are generally not candidates for TKA until the infection is adequately treated and resolved. 
• Uncontrolled Medical Conditions: Uncontrolled medical conditions, such as uncontrolled diabetes, hypertension, or cardiovascular disease, may have increased risk of surgery and the postoperative period. 
• Insufficient Bone Stock: In cases where there is insufficient bone stock or severe bone loss, the stability and longevity of the implant may be compromised, making TKA less suitable. 
• Neurological or Muscular Disorders: Conditions that significantly affect neuromuscular function, such as certain neurological disorders or severe muscle weakness, may impact the success of TKA and rehabilitation. 
• Untreated Coagulopathy: Individuals with untreated coagulopathies or bleeding disorders may be at a higher risk of excessive bleeding during surgery. 
• Psychological or Cognitive Impairment: Individuals with severe psychological or cognitive impairments that may affect their ability to adhere to postoperative rehabilitation protocols and care instructions. 
• Unrealistic Expectations: Patients with unrealistic expectations regarding the outcomes of TKA or those who may not fully understand the postoperative rehabilitation process may not be ideal candidates. 
• Allergic Reactions to Implant Materials: Known allergies to specific implant materials, such as metals or polymers used in the prosthesis, may pose a contraindication to TKA. 

Outcomes

• Pain Relief: The primary goals of TKA is to alleviate chronic and debilitating knee pain associated with conditions like osteoarthritis. Many patients experience a reduction in pain or complete relief after surgery. 
• Improved Function and Mobility: TKA restores joint function and improves mobility, allowing patients to engage in daily activities. The procedure often leads to enhanced range of motion and improved joint stability. 
• Enhanced Quality of Life: TKA has a positive impact on overall quality of life. Patients often report an improved ability to perform routine tasks, participate in recreational activities, and enjoy a more active lifestyle. 
• Correction of Deformities: TKA can correct deformities and malalignments in the knee joint, improving joint mechanics and reducing stress on surrounding tissues. 
• Long-Term Durability: Modern TKA implants and materials are designed for durability, and many patients experience long-lasting benefits. The majority of TKAs remain functional for 15 years or more, and advancements in implant technology continue to improve longevity. 
• Reduced Disability: TKA can significantly reduce disability associated with severe knee arthritis. Patients often regain independence and experience a decrease in limitations imposed by joint pain and dysfunction. 
• Improved Joint Stability: The stability of the knee joint is often improved after TKA, reducing the risk of falls and enhancing overall joint control during activities. 
• Rehabilitation and Return to Activities: While postoperative rehabilitation is crucial, many patients successfully regain strength and function, allowing them to return to activities such as walking, climbing stairs, and participating in low-impact sports. 

Periprocedural planning

Preoperative Assessment: 

1. Medical History: The evaluation of the patient’s medical history, including comorbidities, medications, and allergies, is conducted. A comprehensive physical examination assesses joint function, range of motion, and any existing deformities. 
2. Cardiopulmonary Assessment: Evaluation of cardiovascular and pulmonary function to determine the patient’s fitness for surgery. 
3. Laboratory Tests: Blood tests, including complete blood count (CBC), coagulation studies, and metabolic panels, are performed to assess baseline health and identify any abnormalities. 
4. Imaging Studies: X-rays and other imaging studies help assess the severity of joint damage, deformities, and bone quality. 

Cardiac Evaluation: 

1. Evaluation of Cardiac Risk: Assessing cardiac risk factors and, if necessary, coordinating with a cardiologist for further cardiac evaluation. 
2. Optimizing Cardiovascular Health: Addressing and managing cardiovascular conditions like hypertension, coronary artery disease, & heart failure. 

Nutritional Assessment: 

1. Nutritional Screening: Identifying nutritional deficiencies that may impact wound healing and recovery. Supplemental nutrition may be recommended as needed. 

Dental Evaluation: 

1. Dental Clearance: Assessing and addressing dental issues, as oral health can impact the risk of infection after joint replacement surgery. 

Infection Control: 

1. Screening for Infections: Identifying and treating any existing infections, including skin infections, urinary tract infections, or systemic infections. 
2. Prophylactic Antibiotics: Administering prophylactic antibiotics before surgery to minimize the risk of postoperative infection. 

Medication Management: 

1. Medication Review: Reviewing and adjusting medications, including anticoagulants, antiplatelet agents, and non-steroidal anti-inflammatory drugs (NSAIDs), based on the surgeon’s recommendations. 
2. Pain Management Planning: Developing a plan for postoperative pain management, which may include medications and non-pharmacological interventions. 

Equipment

Orthopedic Instruments: 

• Bone Cutting Guides: Patient-specific or generic cutting guides are used to guide the precise cutting of bone during the surgery. 

• Trial Implants: Temporary implants are used to assess the fit, alignment, and stability of the knee joint before the final implant is placed. 

• Prosthesis Implants: Customized knee prostheses made from materials like metal, plastic, and ceramic are used to replace the damaged joint surfaces. 

Bone Preparation Instruments: 

• Bone Saws: Oscillating or reciprocating saws are used to precisely cut the bone during the surgical procedure. 

• Bone Rongeurs: Surgical instruments with a biting or cutting edge used for trimming and shaping bone. 

• Reamers: Instruments used to prepare the bone to receive the implant by removing damaged or diseased bone. 

Soft Tissue Management Instruments: 

• Tissue Retractors: Surgical instruments used to gently move and hold soft tissues (muscles, tendons, ligaments) away from the surgical site to provide clear visibility. 

• Surgical Scissors and Dissectors: Used for cutting and dissecting soft tissues around the knee joint. 

Cementing Equipment: 

• Bone Cement: Acrylic bone cement is often used to fix the implants to the bone. The cement is mixed and applied during the surgery. 

• Cement Gun and Nozzle: Devices used to deliver and apply bone cement to the prepared bone surfaces. 

Alignment and Measurement Tools: 

• Alignment Jigs: Instruments that assist in achieving proper alignment of the implant components to ensure optimal joint function. 

• Intramedullary Rods: Placed inside the femur to guide the alignment of the femoral component. 

• Extramedullary Guides: Used externally to guide the alignment of the tibial and femoral components. 

Instrument Trays and Sterilization Equipment: 

• Sterilization Containers: Containers used to hold and sterilize surgical instruments before the procedure. 

• Instrument Trays: Customized trays containing the necessary instruments for TKA, organized for efficiency during surgery. 

Power Tools: 

• Surgical Drills and Reamers: Powered instruments used for precise bone preparation and shaping. 

• Sagittal Saw: A powered saw used for making precise cuts in the bone during the surgery. 

Fluoroscopy or Navigation Systems: 

• Fluoroscopy Machines: Real-time imaging systems that use X-rays to provide visual guidance during surgery. 

• Computer-Assisted Navigation Systems: Advanced systems that use computer technology to assist the surgeon in achieving accurate alignment and placement of implants. 

Wound Closure Instruments: 

• Sutures and Staples: Used for closing incisions after the TKA procedure. 

Patient preparation

Anesthesia: 

• General Anesthesia vs. Regional Anesthesia: The choice between general anesthesia and regional anesthesia depends on various factors, including the patient’s overall health, preferences, and the surgeon’s expertise. 
• General Anesthesia: Involves rendering the patient unconscious during the surgery. It is commonly used for TKA and may be preferred in patients who have difficulty tolerating regional anesthesia. 
• Regional Anesthesia: Involves numbing a specific region of the body, providing pain relief without rendering the patient fully unconscious. Regional anesthesia is used in conjunction with sedation, creating a more comfortable and less invasive experience for the patient. 

Positioning: 

• Supine Position: The patient is typically positioned in a supine (lying on the back) position on the operating table. 

• Positioning Devices: Various positioning devices, such as foam pads and cushions, may be used to support and stabilize the patient’s body during the procedure. 
• Leg Positioning: The affected leg is usually placed in a slightly flexed position to facilitate access to the knee joint. 
• Calf Compression Device: A calf compression device may be applied to prevent deep vein thrombosis (DVT) during the surgery by promoting blood circulation. 

Sequential Compression Devices (SCDs): 

• DVT Prevention: SCDs are often applied to lower extremities to reduce the risk of deep vein thrombosis by intermittently compressing the calf muscles and promoting blood flow. 

Monitoring and follow up

Immediate Postoperative Monitoring: 

• Recovery Room Observation: Patients are closely monitored in the recovery room for vital signs, pain control, and initial mobility. 

• Pain Management: Assessing and managing postoperative pain is a priority. Various pain management strategies, including medications and physical therapy, are implemented. 

• Neurovascular Monitoring: Checking for any signs of neurovascular compromise, such as changes in sensation, color, or temperature in the affected limb. 

Hospital Stay: 

• Daily Assessments: During the hospital stay, healthcare providers conduct daily assessments of the patient’s overall condition, wound healing, and pain levels. 

• Physical Therapy: Initiation of physical therapy sessions to promote mobility, strength, and joint range of motion. 

• Medication Management: Monitoring and adjusting medications, including pain medications and prophylactic antibiotics. 

Post-discharge Follow-up: 

• First Follow-up Appointment: Patients typically have a follow-up appointment with the surgeon within the first two weeks after discharge. 

• Wound Check: Ensuring proper wound healing and addressing any signs of infection or complications. 

• Review of X-rays: Radiographic assessment to evaluate the positioning and stability of the implants. 

• Physical Therapy Continuation: Continuation of outpatient physical therapy to support ongoing rehabilitation. 

Intermediate Follow-up (6 Weeks to 3 Months): 

• Clinical Assessment: Evaluating the patient’s overall progress, including pain levels, joint function, and mobility. 

• Radiographic Evaluation: Continued monitoring of implant position and stability through X-rays. 

• Physical Therapy Advancement: Adjusting and advancing the physical therapy program based on the patient’s capabilities. 

Long-Term Follow-up (Beyond 3 Months): 

• Clinical Assessment: Regular clinical assessments to monitor long-term outcomes, including pain relief, joint function, and overall satisfaction. 

• Radiographic Surveillance: Periodic X-rays to assess the condition of the implants. 

• Functional Assessments: Evaluating the patient’s ability to perform activities of daily living and engage in recreational activities. 

• Complication Surveillance: Monitoring for potential complications such as infection, implant loosening, or instability. 

TECHNIQUE

Step:1- Preoperative Planning: 

• The orthopedic surgeon reviews the patient’s medical history, performs a physical examination, and assesses imaging studies, such as X-rays and MRI, to determine the extent of joint damage. The surgical team selects the appropriate implant components based on the patient’s anatomy and the severity of the knee joint degeneration. 

Step: 2. Anesthesia: 

• The patient is brought into the operating room and administered either general anesthesia or regional anesthesia, depending on the surgeon’s and patient’s preference. Regional anesthesia may include spinal or epidural anesthesia, providing pain relief while allowing patient to remain awake. 

Step: 3. Incision: 

• A midline incision is made over the knee joint. The length & location of incision may vary depending on the surgical approach chosen by the surgeon. 

Step: 4. Exposure and Visualization: 

• The surgeon carefully dissects through the layers of tissue to expose the knee joint, taking care to preserve surrounding muscles and ligaments. Special retractors are used to provide optimal visualization of the joint. 

Step: 5. Resection of Damaged Joint Surfaces: 

• Damaged bone and cartilage is removed from femur (thigh bone), tibia (shin bone), and patella (kneecap) using precision cutting instruments. Resection is performed to create flat, even surfaces for the placement of the artificial components. 

Step: 6. Bone Preparation: 

• Specialized instruments, including cutting guides and drills, are used to shape the bone to precisely fit the prosthetic components. The surgeon may use trial implants to check for proper fit, alignment, and stability before placing the final components. 

Step: 7. Implant Placement: 

• The femoral, tibial, and patellar components (made of metal and plastic) are secured to the prepared bone surfaces using bone cement or, in some cases, press-fit techniques. The patella may be resurfaced with a plastic component to improve joint function. 

Step: 8. Closure of Incision: 

• The incision is closed with the staples or sutures. Sterile dressings are applied to the wound. 

Step: 9. Postoperative Recovery: 

• The patient is transferred to the recovery room for monitoring. Pain management strategies, including medications and regional blocks, are initiated. Physical therapy is initiated to promote early mobilization and joint function. 

Postoperative Care

Immediate Postoperative Period: 

• Pain Management: Adequate pain control is essential. Intravenous or oral pain medications are administered, and regional anesthesia techniques may be continued. 
• Neurovascular Monitoring: Regular checks for signs of neurovascular compromise, such as changes in sensation, color, or temperature in the affected limb. 

Wound Care: 

• Dressing Changes: The surgical incision is typically covered with a sterile dressing, which is monitored for any signs of bleeding, infection, or other issues. 
• Suture or Staple Removal: Depending on the type of closure, sutures or staples may need to be removed at a follow-up appointment. 

Early Mobilization: 

• Ambulation: Encouraging the patient to stand and walk with assistance as soon as possible after surgery, typically on the same day or the day after. 
• Physical Therapy: Initiation of physical therapy exercises to improve joint mobility, strength, and gait. 

Deep Vein Thrombosis (DVT) Prophylaxis: 

• Anticoagulant Medication: Administration of anticoagulant medications to prevent blood clots. 
• Compression Devices: Use of intermittent pneumatic compression devices on the lower extremities to enhance blood circulation. 

Pain Management: 

• Multimodal Approach: Utilizing a combination of medications, including analgesics, anti-inflammatories, and, if necessary, opioids. 
• Regional Anesthesia: Continuous infusion or intermittent injections of regional anesthesia may be used for targeted pain relief. 

Home Exercises and Activity Modification: 

• Home Exercise Program: Providing the patient with a set of prescribed exercises to perform at home to enhance recovery and joint function. 
• Activity Modification: Advising on precautions and restrictions, including weight-bearing limitations and specific movements to avoid. 

Continuation of Rehabilitation: 

• Outpatient Physical Therapy: Continuing physical therapy sessions on an outpatient basis to progress rehabilitation and address specific functional goals. 
• Joint Range of Motion Exercises: Focus on improving and maintaining joint flexibility. 

Complications

Infection: 

• Superficial or Deep Infection: Infections can occur at the surgical site. Superficial infections may be treated with antibiotics, while deep infections may require surgical intervention, such as debridement or, in severe cases, removal of the implant. 

Thromboembolism: 

• Deep Vein Thrombosis & Pulmonary Embolism: Blood clots can form in veins of the legs (DVT) and potentially travel to the lungs (PE). Prophylactic measures, such as anticoagulant medications and compression devices, are used to minimize this risk. 

Joint Stiffness: 

• Arthrofibrosis: Excessive scar tissue formation in the joint can result in stiffness, limiting the range of motion. Physical therapy and, in some cases, manipulation under anesthesia may be necessary. 

Instability: 

• Joint Instability: Imbalance in soft tissues or improper component positioning can lead to joint instability, causing pain and difficulty with activities. Revision surgery may be needed to correct instability. 

Nerve or Blood Vessel Injury: 

• Peripheral Nerve Damage: Nerves near the surgical site may be injured, leading to numbness, tingling, or weakness. 
• Vascular Injury: Rarely, blood vessels may be damaged during surgery, requiring immediate intervention. 

Allergic Reactions: 

• Metal Allergy: Some patients may have an allergic reaction to metal implants, leading to inflammation and discomfort. Alternative implant materials may be considered in such cases. 

Persistent Pain: 

• Chronic Pain: Some patients may experience persistent pain after surgery, which could be due to various factors such as nerve irritation, implant issues, or complex regional pain syndrome (CRPS). 

Wound Healing Issues: 

• Delayed Healing: Wound healing complications, such as delayed wound closure or dehiscence, may occur. Proper wound care and, in severe cases, surgical intervention may be necessary. 

References

Total Knee Arthroplasty Techniques – StatPearls    

Knee Arthroplasty – StatPearls 

References

Total Knee Arthroplasty Techniques – StatPearls    

Knee Arthroplasty – StatPearls