Knee Arthroscopy
Arthroscopy is useful in evaluating and treating the following conditions
- Torn floating cartilage (meniscus): The cartilage is trimmed to a stable rim or occasionally repaired
- Torn surface (articular) cartilage
- Removal of loose bodies (cartilage or bone that has broken off) and cysts
- Reconstruction of the Anterior Cruciate ligament
- Patello-femoral (knee-cap) disorders
- Washout of infected knees
- General diagnostic purposes
Basic Knee Anatomy
Investigations
Meniscal Cartilage Tears
Following a twisting type of injury the medial (or lateral) meniscus can tear. This results either from a sporting injury or may occur from a simple twisting injury when getting out of a chair or standing from a squatting position. Our cartilages become a little brittle as we get older and therefore can tear a little easier. The symptoms of a torn cartilage include
- Pain over the torn area i.e. inner or outer side of the knee
- Knee swelling
- Reduced motion
- Locking if the cartilage gets caught between the femur a tibia
Once a meniscal cartilage has torn it will not heal unless it is a very small tear that is near the capsule of the joint. Once the cartilage has torn it predisposes the knee to develop osteoarthritis (wear and tear) in 15 to 20 years. It is better to remove torn pieces from the knee if the knee is symptomatic.
Torn cartilages in general continue to cause symptoms of discomfort, pain and swelling until the loose, ragged pieces are removed. Only the torn section is removed and the knee should recover and become symptom free. If the entire meniscus is removed, the knee will develop osteoarthritis in 15 to 20 years. It is standard to remove only the torn section of cartilage in the hope that this will delay the onset of long-term wear and tear osteoarthritis.
Occasionally, provided the knee is stable and the tear is a certain type of tear in a young patient (peripheral bucket handle tear), the meniscus may be suitable for repair. If repaired, one has to avoid sports for a minimum of three months.
Articular Cartilage (Surface) Injury
If the surface cartilage is torn, this is most significant as a major shock-absorbing function is compromised. Large pieces of articular cartilage can float in the knee (sometimes with bone attached) and this causes locking of the joint and can cause further deterioration due to the loose bodies floating around the knee causing further wear and tear. Most surface cartilage wear will ultimately lead to osteoarthritis. Mechanical symptoms of pain and swelling due to cartilage peeling off can be helped with arthroscopic surgery. The surgery smoothes the edges of the surface cartilage and removes loose bodies.
Anterior Cruciate Ligament Injuries
Rupture of the Anterior (rarely the posterior) Cruciate Ligament (ACL) is a common sporting injury. Once ruptured the ACL does not heal and usually causes knee instability and the inability to return to normal sporting activities. An ACL reconstruction is required and a new ligament is fashioned to replace the ruptured ligament. This procedure is performed using the arthroscope.
Patella (knee-cap) Disorders
Inflammatory Arthritis
Bakers Cysts
Newer Techniques
Isolated areas of articular cartilage loss can be repaired using cartilage transplant technology. This is a new and exciting field that is developing in the treatment of specific isolated cartilage defects in younger patients
The process is called Autologous Chondrocyte Grafting . It involves harvesting cartilage cells from the affected knee, sending these cells to a laboratory, and then culturing the cells to multiply into many cells. The large amount of cells produced are then placed back into the affected knee into the defect requiring resurfacing. Results are still short-term follow-up but are looking encouraging.
After a major cartilage or ligament injury has been treated the knee can return to normal function. There is however a small increase in the risk of developing long-term wear and tear (Osteoarthritis) and depending on the degree of injury activity modification may be required. Activities that help prevent knees from deteriorating quickly include:
- Low impact sports like swimming, cycling and walking
- Reducing weight and maintaining a healthy diet
Arthroscopy of the Knee: Patient Information
Post-operative Recovery
Risks of Arthroscopy
- Postoperative bleeding
- Deep Vein Thrombosis
- Infection
- Stiffness
- Numbness to part of the skin near the incisions
- Injury to vessels, nerves and a chronic pain syndrome
- Progression of the disease process
Post –Operative Exercises and Physical Therapy