What is Arthroscopic Knee Surgery?
Arthroscopic knee surgery refers to the surgical procedure that involves the removal of the joint surfaces of the three knee bones and their replacement with metal and plastic components.
This treatment option, known as knee prosthesis, is considered suitable for individuals who have not responded to medication, intra-articular injections, and physical therapy for osteoarthritis, as well as those who have not experienced satisfactory outcomes from knee arthroscopy and realignment surgeries, or have experienced recurrent symptoms following these procedures. It is deemed necessary to opt for knee replacement if alternative treatments have proven ineffective and if the individual’s knee issues significantly impair their quality of life. In modern practice, the lifespan of prostheses is estimated to extend up to 20-25 years, rendering the concept of life quality more significant than the chronological age of the patient. However, individuals under the age of 55 should exhaust all other available treatment options before considering knee replacement. Between the ages of 55 and 65, alternative treatment methods may offer certain advantages. Individuals aged 65 and above can undergo knee replacement surgery without major concerns.
The frequently asked question pertains to the appropriate age for knee replacement and the expected longevity of the prosthesis. In addressing this query, the patient’s specific characteristics, including age, gender, weight, and activity level, play a determining role. For instance, it can be suggested that individuals aged 65 and above, female patients, those weighing less than 70 kg, and individuals with limited physical activity can generally manage with the remaining lifespan of the prosthesis. When knee replacement surgery is performed using contemporary techniques and high-quality prostheses, a pain-free life with full knee functionality can typically be achieved for approximately 20-25 years.
A healthy knee joint is supported by four ligaments, ensuring proper connection and coordination between the bone structures. However, in the case of an arthritic knee, these ligaments may become compromised. During knee replacement surgery, some of these ligaments are excised along with the joint surfaces, subsequently replaced with new synthetic surfaces. To secure the implanted components in place, two methods are commonly employed. The first approach involves the use of a cement known as polymethylmethacrylate for fixation, while the second method entails the utilization of specially designed prostheses that integrate with the bone’s developmental process.
Today, the majority of knee prostheses are predominantly cemented. Cemented prostheses exhibit excellent compatibility and can provide a lifespan of up to approximately 25 years. However, this duration is subject to variation based on factors such as patient weight, overall health status, and activity levels. The advantage of cement lies in its ability to create a robust interface between the prosthesis and bone, imparting biomechanical strength. Moreover, the contemporary materials employed in prosthetic construction demonstrate minimal susceptibility to fracture incidents.
During the 1980s, a class of prostheses emerged that could be implanted without the use of cement. These implants incorporated biologically active agents on their surfaces to facilitate the initiation of new bone formation. Additionally, diverse screw systems were developed to ensure secure fixation of the implants within the bone structure. The screws played a pivotal role in maintaining implant stability until the establishment of new bone tissue. Certain models achieved comparable outcomes to cemented prostheses, notwithstanding the presence of occasional small fragments resulting from load-bearing and the expeditious onset of biological response. Furthermore, comprehensive long-term data concerning the efficacy of these prosthetic variants remains limited at present.
In the late 1980s, hybrid prostheses were developed, with the femoral component being cementless and the tibial component being cemented. The long-term outcomes of these prostheses have been satisfactory.
In summary, knee prosthesis surgery is an effective treatment approach for regulating knee biomechanics.
Patients are encouraged to walk on the day following the surgery and resume normal activities, such as sitting on the toilet, on the second day. The sutures are typically removed within approximately 15 days, allowing the patient to take baths.
Early postoperative rehabilitation begins on the day after the surgery, focusing on knee flexion and muscle strengthening exercises. These exercises continue until complete restoration of knee function is achieved, which is typically observed by the sixth week. While patients may experience swelling and be aware of the presence of the prosthesis for a period of 3-6 months, walking becomes painless after the initial week.
WARNINGS FOR PATIENTS CONSIDERING SURGERY
Potential cautions and early complications during and post-operation:
Infection: The infection rate in prosthetic surgeries conducted under optimal operating room conditions is approximately 2%. Optimal operating room conditions imply the presence of specialized measures like “laminar air flow,” which effectively prevent microbial contamination. Conversely, infection rates in standard operating rooms range between 5% and 10%. In the event of an infection, it may necessitate a subsequent procedure to cleanse the joint. Severe infections may require the removal of the implanted prosthesis. Following a 6-12 week course of antibiotic treatment, a replacement prosthesis can be considered.
To mitigate the risk of infection, antibiotics are administered intravenously during anesthesia and continued post-surgery. Additionally, meticulous attention is given to instrument sterilization procedures to ensure optimal safety measures.
Deep vein thrombosis (DVT), characterized by blood clot formation in the deep veins, occurs in less than 5% of cases. Typically, its onset is observed after the third postoperative day, with a peak incidence between days 6 and 10. However, in rare instances, DVT may manifest even months following the surgery. Among these cases, approximately 5-10% entail the detachment of the thrombus, posing a life-threatening risk if it embolizes to vital organs such as the lungs or brain. Certain individuals exhibit additional predisposing factors, including the use of oral contraceptives in women, prior history of DVT, presence of varicose veins, familial predisposition, among others.
To mitigate the risk of DVT, preventive measures encompass the administration of anticoagulant medication, application of postoperative anti-embolic stockings, implementation of in-bed exercises, and early mobilization with controlled weight-bearing. In patients with additional risk factors, these preventive strategies may be further extended.
Technical errors: Potential complications in prosthetic surgeries, given their intricate nature. However, the likelihood of complications resulting from technical errors significantly diminishes under the expertise of skilled surgeons, with consequential technical errors being exceedingly rare and seldom impacting the overall outcome.
Postoperative Period
Following the admission of patients to the operating room, they undergo sedation, and the relevant leg is prepared through sterilization procedures, including wiping and draping. Subsequently, the surgical equipment and instruments are set up, requiring an average duration of approximately 40 minutes. In the hands of experienced surgeons, the typical duration of the operation is around 2 hours. After the procedure, patients spend approximately 30 minutes to 1 hour in the recovery room before being transferred to their assigned rooms. It is worth noting that patients with underlying medical conditions or advanced age may occasionally necessitate intensive care support.
Upon settling into their rooms, patients regain full consciousness within a span of 2 hours. Adequate pain management is ensured through the administration of appropriate analgesics. Additionally, patients may have a drain in place to evacuate any accumulated blood, an elastic bandage applied, and anti-embolic stockings worn on the operated leg (specific practices may exhibit variability across different clinical settings). Within 3-4 hours post-operation, patients are provided with meals to meet their nutritional needs. The subsequent day, patients are granted permission to initiate mobility with the aid of a walker. Prior to standing up, a precautionary measure involves allowing the patient to sit for approximately 5 minutes to ensure the absence of dizziness. In the event of dizziness, the patient should promptly assume a supine position and reattempt standing after an interval of one hour.
Following the surgical procedure, patients are initially anesthetized and the relevant leg is prepared and covered for a sterile environment. Subsequently, the surgical systems are set up, which typically takes approximately 40 minutes. In the hands of experienced surgeons, the average duration of the operation is around 2 hours. After the surgery, patients are kept in the recovery room for 30 minutes to 1 hour before being transferred to their assigned rooms. In some cases, patients with underlying health conditions or advanced age may require intensive care.
Within 2 hours of being admitted to their rooms, patients fully regain consciousness. Pain is effectively managed through the use of analgesics. To drain accumulated blood from the knee (practice may vary in clinics), a drain, elastic bandage, and anti-embolism stockings are applied. After 3-4 hours, patients are provided with meals. On the following day, patients are allowed to get up with the assistance of a walker. Before standing up, it is important to ensure there is no dizziness by sitting for approximately 5 minutes. If dizziness occurs, patients should lie down and attempt to stand up again after 1 hour.
During the hospital stay (usually 5-7 days, although practices may differ), a physiotherapist visits patients on the second day and demonstrates exercises to be performed in bed. Additionally, a Continuous Passive Motion (CPM) device is attached to the knee to facilitate controlled movement. Patients are instructed to use the device’s remote control to gradually increase the knee’s range of motion from 30 degrees, with 2-hour intervals. By the second or third day, the knee should achieve a flexion angle of 90-100 degrees. The drain is typically removed on the second or third day, and the knee is regularly iced. It is normal to experience a temperature of approximately 38 degrees Celsius during the first two nights, which does not necessarily indicate an infection. Signs of infection generally appear on the third day.
After returning home, patients can lie down or sit with their leg extended until the 10th day post-surgery. During this period, they should continue applying ice to the knee. While eating, patients can sit with their foot on the floor and utilize a walker for mobility. It is crucial not to remove the bandage and stocking on the knee to prevent potential bleeding and swelling. Patients should diligently perform the prescribed exercises on a daily basis. It is important to adhere to the prescribed blood-thinning medication and take the prescribed pain medication if necessary. Any temperature exceeding 38 degrees Celsius, along with knee or leg pain and swelling in the toes, should prompt immediate communication with the attending physician.
After approximately 15 days, your surgical incision will be assessed by your doctor, and if deemed appropriate, the sutures will be removed. Subsequently, you will commence a course of physical therapy. Typically, physical therapy sessions are conducted three times a week and continue until the conclusion of the third month. It is imperative to receive physical therapy from skilled physiotherapists as it represents a crucial determinant of optimal outcomes.
Around the third week, you may transition from employing a walker to relying on a single crutch. It is advisable to utilize the crutch on the unaffected side. In cases where bilateral surgery was performed, the walker can be utilized until the sixth week. Within the 6-12 week timeframe, gradual abandonment of the crutch is feasible. However, should you find a sense of enhanced security with its use, extended periods of crutch utilization may be permissible. By the eighth week, increased activity levels can be anticipated, including resumption of driving, yet caution should still be exercised regarding vigorous athletic pursuits. Towards the conclusion of the fourth month, gradual reintegration into sports activities can be initiated under the guidance of your physiotherapist. Full resumption of sporting activities is typically achieved around the six-month mark.
