Knee Arthroscopy
Healthcare providers use knee arthroscopy to diagnose and treat a wide range of knee injuries. During arthroscopic knee surgery, your healthcare provider inserts a tiny camera through an incision. The camera shows the inside of your knee. The images appear on a screen in the operating room. They help your healthcare provider diagnose problems inside of your knee.
Knee arthroscopy is a very common minimally invasive surgical procedure. Minimally invasive procedures require smaller incisions (cuts) than traditional surgery. The incisions are about the size of a keyhole.
To treat injuries or structural problems, your healthcare provider inserts tiny tools through another incision. They use the tools to repair or remove damaged tissue.
Who needs knee arthroscopy?
Your healthcare provider may recommend knee arthroscopy if you have knee pain that doesn’t get better with nonsurgical treatments. Nonsurgical treatments include rest, ice, nonsteroidal anti-inflammatory drugs and physical therapy (PT). Although arthritis causes knee pain, arthroscopic knee surgery isn’t always an effective treatment for osteoarthritis.
Healthcare providers use arthroscopy to get a better look at cartilage, bones and soft tissues inside of your knee. They use the procedure to diagnose several types of knee injuries. Most of these injuries affect ligaments and cartilage in your knee joint.
Knee injuries among athletes (including adolescents) are very common. They can happen in contact sports and those that require jumping, such as volleyball.
Why do providers use knee arthroscopy?
Your healthcare provider uses knee arthroscopy to:
Diagnose injuries: During knee arthroscopy, your healthcare provider takes a close look at any painful or swollen areas. The camera shows images of damaged soft tissues and bones. The images help your healthcare provider diagnose injuries (or confirm a diagnosis) and plan treatment.
Repair injured soft tissues and bones: If you need surgery to repair tendons, ligaments or cartilage, your healthcare provider uses specially designed tools. The camera shows real-time images that guide your healthcare provider during the procedure. Your healthcare provider uses tiny tools to repair and reconstruct soft tissues by stitching them together. They can also suture (stitch) bones together.
Remove damaged or inflamed tissue: Some tiny tools help your healthcare provider shave off damaged bone and cartilage or inflamed tissue (such as the synovium). They use tools to remove these tissues from your knee.
What conditions does knee arthroscopy treat?
You may need knee arthroscopy if you have:
Soft tissue injuries: Soft tissues include ligaments (they connect bones to bones) and tendons (they connect muscles to bones). Some of the most common knee injuries are bursitis, torn meniscus, patellar tendonitis, anterior cruciate ligament tear (ACL tear) and tears of the medial collateral ligament (MCL tear).
Fracture: Bones can break or chip off inside of your knee. Sometimes, pieces of cartilage (rubbery tissue that helps bones move against each other smoothly) can break off when your bone fractures.
Inflammation: The synovium inside a joint can become inflamed (swollen and irritated). Synovium is soft tissue on the inside of a joint. Healthcare providers call this condition synovitis.
ACL Reconstruction
Your knee is a hinge joint where the end of the thigh bone (femur) meets the beginning of the large bone in your lower leg (tibia). A healthy knee has smooth cartilage that covers the ends of the femur and tibia. The smooth cartilage lets the surfaces of the two bones glide smoothly as you bend your knee. The muscles and ligaments around the knee joint support your weight and help move the joint smoothly so you can walk without pain.
The Anterior Cruciate Ligament (ACL) is located in the center of the knee joint where it runs from the backside of the femur (thighbone) to connect to the front of the tibia (shinbone).
The need for surgery depends on the severity of the ACL tear and the lifestyle of the patient. A completely torn ACL cannot heal on its own. Studies have shown, however, that in some young patients who experience a partial tear of the ACL, the ligament may heal without the need for surgery. In patients who have only a partial tear, nonsurgical treatment may be an option.
Patient lifestyle: People who have completely torn their ACL and who maintain an active lifestyle – especially competitive athletes – will be recommended for surgery to allow them to return to their prior level of activity and avoid future injury. Young patients who participate in cutting and pivoting sports (soccer, basketball, lacrosse, football) are at increased risk of meniscus injury if an ACL tear is left untreated. In some older patients or others whose lifestyles do not include rigorous exercise with side-to-side movements, nonsurgical treatments may allow them to return to normal routines without an intact ACL. Patients who participate in running, cycling, weightlifting, or exercise classes are able to return to these activities with a low risk of new injury.
HSS research enhances surgical outcome predictions: In a two-year patient study, HSS physician researchers tested the ability of machine learning algorithms to help predict which patients might experience significant improvement in their knee function after ACL reconstruction. Several of these, and especially elastic-net penalized logistic regression (ENPLR) algorithm proved useful and are now employed in the surgical decision-making process. In the study, they found that the most common factors that may predict a patient’s improvement after surgery (“minimal clinically important difference” or MCID) are semi-modifiable and can assist with preoperative shared decision making between the surgeon and patient to better prepare the knee before surgery. In addition, the ENPLR algorithm was able to use data gathered from the patient before surgery and the postsurgical outcome scores reported by prior patients to predict the benefit of surgery, including return-to-play timing and other outcomes.
For a complete tear of the ACL, reconstruction surgery is generally scheduled between 3 to 6 weeks after the injury occurs. This allows inflammation in the area to subside and allows time for physical therapy sessions to focus on restoring normal knee flexion and extension. If surgery is performed too early and in patients with limited knee range of motion, patients may develop a profound scarring response called arthrofibrosis, which leads to stiffness of the knee joint. Delaying surgery beyond three months increases the risk of developing irreparable cartilage damage or meniscus injuries because of continual instability in the knee.
Orthopedic surgeons gauge the appropriate timing of reconstruction surgery based on:
- Whether there are other injuries present that need to be treated first
- The physical appearance of the knee (how much swelling is present)
- The patient’s level of knee pain
- The patient's range of motion and quality of muscle control when flexing (bending) or extending (straightening) the leg
Some evidence suggests that delaying ACL reconstruction surgery for six months or longer after injury can not only increase the risk of sustaining a meniscus tear or cartilage injury, but also lead to increased risk of the need for a future ACL revision surgery.
In ACL reconstruction surgery, a new ACL is made from a graft of replacement tissue from one of two sources:
- A portion of the patient's own iliotibial band, hamstring, quadriceps or patellar tendon
- An allograft (tissue from a human organ donor)
The type of graft used for each patient is determined on a case-by-case basis, however allograft tissue is not advised for young patients due to the significantly higher risk of reinjury and graft failure.
ACL reconstruction surgery is performed using minimally invasive arthroscopic techniques, in which a combination of fiber optics, small incisions and small instruments are used. A somewhat larger incision is needed, however, to obtain the tissue graft. ACL reconstruction is an outpatient (ambulatory) procedure, in which patients can go home on the same day as their surgery.
Meniscus Surgery
The meniscus is a soft, rubber-like C-shaped cushion in between the bones of the knee. There are two of them – one on the inner side (medial meniscus) and one on the outer side (lateral meniscus). These structures act as shock absorbers. They share the load on the knee and protect the cartilage cap over the knee bones. There are two problems which occur in menisci – one, that it degenerates (becomes weak) with age, and the other that it tears due to injury.
A degeneration in the meniscus causes pain, having become softer it often breaks with minimum injury. A typical meniscus tear occurs in young adults, as a result of twisting injury.
You’ll need some or all of the following tests before your meniscus surgery:
- Physical exam
- Blood tests
- EKG
- Chest X-ray
- Knee X-ray
- MRI
Tell your provider and surgeon what medications and over-the-counter (OTC) or herbal supplements you take. You may have to stop taking some prescriptions or supplements before your surgery.
Your surgeon will tell you when you should fast (stop eating and drinking) the day before your surgery. Most people need to fast for 12 hours before their surgery.
Plan to arrange transportation to and from your surgery. You won’t be able to drive yourself home after surgery, so make sure someone’s available to pick you up.
The day of your surgery, an anesthesiologist will give you anesthesia to numb your body and make sure you don’t feel pain during the procedure. They’ll give you either general anesthesia that puts you to sleep or regional anesthesia that numbs you from the waist down. If you need regional anesthesia, your anesthesiologist will also give you a sedative to relax you.
Meniscus surgery is usually done with a minimally invasive knee arthroscopy. Your surgeon will make a few cuts (incisions) in the skin around your knee. They’ll insert tiny tools and a small camera into your knee joint to treat the meniscus tear. There are three types of meniscus surgery:
- Meniscus repair
- Partial meniscectomy
- Meniscus replacement
Meniscus repair: A meniscus repair is just what it sounds like — your surgeon will repair the tear and any other damage in your meniscus. They’ll stitch (suture) the tear together so your meniscus heals back into one piece. Your body will absorb the sutures as the tear heals.
Partial meniscectomy: A “partial meniscectomy” is the medical term for removing the damaged part of your meniscus. Your surgeon will trim the damaged cartilage away from your meniscus and leave healthy tissue in place. Meniscectomy is a good option for more severe tears. Higher-grade meniscus tears usually are too severe to heal back together completely, even with a repair.
Meniscus replacement: Meniscus replacement (meniscus transplantation) is much less common than the other two types. It’s usually only a good option for people younger than 50 who have knee arthritis or a severely torn meniscus. Your surgeon will replace your meniscus with an allograft (a meniscus from a human donor).
Meniscus surgery usually takes around an hour. It might take a little more or less time depending on which type of surgery you need, the severity of the tear and if you have any other injuries (like knee ligament tears) that need treatment, too.
Meniscus surgery is usually an outpatient procedure. That means you can go home the same day. Your surgery team will monitor you in a recovery room while the anesthesia wears off. When it’s safe for you to go home, you’ll need someone to drive you.
