Knee arthroscopy
Introduction
Arthroscopy has revolutionized orthopedics. During arthroscopy of the knee, a small camera is inserted into the joint, allowing the doctor to see the inside of the joint by making only a little incision. The knee was the first joint in which an arthroscope was widely used both for diagnosis of problems and repair of damage.
Anatomy
The knee is the joint between the femur (above) and the tibia (below). There is a kneecap in front of the joint. Large thigh muscles allow to move the knee. The joint is surrounded by an articular capsule formed by the ligaments, connective tissue and synovial tissue. During arthroscopy, the articular capsule is filled with sterile physiological saline, which makes knee arthroscopy an “underwater” operation, because all interventions are carried out in a saline environment. During the procedure, the doctor can see almost all the structures of the joint, including: the surfaces of the tibia, femur and patella, both menisci, anterior and posterior cruciate ligaments, and synovial lining. There are menisci – medial and lateral – located between the articular surfaces, on both sides. The meniscus has a protective, shock-absorbing and stabilizing function. The articular surfaces are covered with the articular cartilage – a smooth, slippery material. The articular cartilage allows the surfaces of the joint to slide against each other without damaging any of them. The ligaments are strong strands of the tissue that connect the ends of bones together. The anterior cruciate ligament (ACL) is located in the center of the knee joint where it runs from the back of the femur to connect to the front of the tibia. The ACL runs through a special indentation in the femur called the intercondylar notch and attaches to the tibia. The aim of the ACL is to block excessive forward movement of the tibia in relation to the femur and to stabilize the knee during movement. The posterior cruciate ligament (PCL) is located close to the back of the knee. It attaches to the back of the femur and the back of the tibia, back from the ACL. The PCL is the main knee stabilizer and controller for how far back the tibia moves relative to the femur.
What is the purpose of arthroscopy?
Currently, knee arthroscopy is used not only to confirm diagnosis, but above all to perform a wide range of procedures, such as removal of free bodies, removal or repair of a damaged meniscus, reconstruction of ruptured ligaments, repair of articular cartilage or treatment of patella damage. The arthroscopy image is magnified and allows the doctor to look more closely at the joint structures. Smaller incisions and precise movements cause less damage to the healthy tissue and shorten the process of healing. However, arthroscopy is only a tool. The results of procedure depend on the underlying problem and the possibilities of treatment. Postoperative rehabilitation also plays an important role.
What do you need to know before the surgery?
You and your doctor should take a joint decision about the surgery. You ought to learn as much as possible about the procedure. If you have concerns or questions, be sure to discuss them with your doctor. There are several steps you need to take after deciding on surgery. Your doctor may order additional examinations and consultations. This is all to make sure you are able to undergo surgery and to minimize the risk of complications. On the day of the procedure, early in the morning, you will be admitted to the Diagnostic and Treatment Department. You should not eat or drink after midnight the night before.
What happens during the procedure?
Before the procedure, the patient will be subjected to general or spinal anesthesia. A decision on the type of anesthesia is made by an anesthesiologist based on a pre-surgery interview – the so-called qualification for anesthesia, during which the most optimal method of anesthesia is chosen. An orthopedist starts the operation by making two small incisions in the knee, they are called portals. Portals are the sites through which an arthroscope and surgical instruments are introduced into the knee. An arthroscope is an oblong instrument with a diameter of about 5 millimeters. An fiber-optic cable located inside an arthroscope allows to connect bright light and a camera. The camera displays the image from the inside of the knee joint on the screen. At the end of the procedure, arthroscopic portals are closed with sutures. A drain, which is a flexible tube connected to a plastic bottle, is usually left in one of the portals. It collects an excess of blood from the knee in the postoperative period. Drains are usually removed the day after surgery.
What happens after the surgery?
Arthroscopy of the knee is usually performed on the day of admission, the next day, after changing the dressing, the patient is discharged home. More complicated ligament reconstructions require a short stay in hospital to better control pain and monitor the condition of the patient.
Crutches are commonly used after knee arthroscopy in order to help patients to move during the recovery period and to relieve the operated limb. Patients who have undergone more complicated reconstructive surgery may be instructed not to put strain on the operated limb for several weeks (which means that they cannot transfer the body weight to the operated limb – they walk with elbow crutches). After ligament reconstructions, patients often need an additional orthosis to control the range of motion in the knee.
In the Szpital Zakonu Bonifratrów, arthroscopy of the knee is performed by a team of specialists in orthopedics and traumatology:
Stanisław Szymanik, MD – Head of the Diagnostic and Treatment Department
Michał Latos, MD
Michał Starmach, MD