The Knee Joint
The knee joint is made up of your thigh bone (femur) and your shin bone (tibia). The tibia swings on the femur creating the bending and straightening mechanism of your knee. On top of the femur bone, there is also a smaller joint known as the patellofemoral joint, where the kneecap (patella) sits on the femur. The ends of the femur, tibia and patella, which make up the knee joint, are lined with cartilage, held together by ligaments and surrounded by muscles.
Inside the knee joint, there are 2 pieces of extra cartilage called the menisci, which allow the joints to glide smoothly on each other. There is an inside, or medial, meniscus; and an outside, or lateral, meniscus. The menisci act to provide extra cushioning to the knee, and to stabilize the joint.
A variety of ligaments hold the knee together. Their primary responsibility is to provide stability to the joint. The main ligaments of the knee are:
- The MCL (Medial Collateral Ligament) which runs on the inside surface of the knee
- The LCL (Lateral Collateral Ligament) which runs on the outside surface of the knee
- The ACL (Anterior Cruciate Ligament) which holds the inside of the joint together
- The PCL (Posterior Cruciate Ligament) which also holds the inside of the joint together
- The Patellofemoral Ligaments, which hold the kneecap to the knee
The muscles that attach around the knee are some of the largest muscles in the body. They include:
- The Quadriceps Muscle on the front of the thigh
- The Hamstring Muscles on the back of the thigh
- The Gastrocnemius Muscles in the calf
Causes of Knee Pain
The knee can become damaged or painful from a traumatic injury like a fall, sports injury, or from wear and tear. The most common causes of injury to the knee include:
- A ligament sprain – including the MCL, LCL, ACL or PCL ligaments
- A muscle strain – such as a quadriceps or hamstring strain or tear
- A meniscal injury – such as a meniscus tear
- A problem with the patellofemoral joint, often called patellofemoral syndrome
- Arthritis of the knee, which affects that cartilage in the knee and the meniscus tissue
KNEE LIGAMENT INJURIES
Knee ligament injuries most commonly occur from a traumatic injury to the knee such as a fall, or from a sports injury.
The MCL and LCL Ligaments
The Medial Collateral Ligament (MCL) and the Lateral Collateral Ligament (LCL) are 2 commonly injured structures in the knee. The collateral ligaments are positioned on either side of the knee joint. The MCL is more easily injured than the LCL. Injury to the MCL is most often caused by a blow to the outside of the knee, which often happens in contact sports like football or hockey. This stretches and tears the ligament on the inner side of the knee. The LCL ligament would be injured in the opposite way.
When injury to the Medial Collateral Ligament (MCL) occurs, one may feel a pop and the knee may buckle sideways. Pain and swelling are common on the inside of the knee. A thorough examination is essential to determine the nature and extent of the injury. Various tests can be performed by your physiotherapist to confirm a diagnosis.
The ACL and PCL Ligaments
The Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL) are strong, tough stabilizers, which are located in the middle of the knee joint. The ACL is most often stretched, torn, or both, by a sudden twisting motion (for example, when the foot is planted one way and the knee is twisted the other way). The PCL is most often injured by direct impact, (for example, in an automobile accident when the knee hits the dashboard of the car).
Injury to a cruciate ligament may cause mild to severe pain, and is usually associated with significant swelling and bruising around the knee. One may hear a popping sound in the knee when injured, and the leg usually feels unstable and may buckle when standing on it. Often times, ACL injuries can occur along with an injury to the MCL and/or the meniscus.
KNEE MENISCUS INJURIES
The menisci are structures that fill the space between the femur (the large bone of the upper thigh) and the tibia (the shin bone). They are made of cartilage much like the rubbery tissue in your nose or earlobe. There is a lateral meniscus on the outside of the knee and a medial meniscus on the inside of the knee. The menisci act as shock absorbers in the knee joint, and also help to stabilize the joint. Specific movements or positions of the knee will stress either the lateral or the medial meniscus. If these movements are taken to the extreme of the range of motion, the menisci can be torn or irritated.
Meniscal injuries happen in a variety of ways, usually involving a forceful twisting inwards, while the knee is flexed and the foot is planted. These injuries are common amongst the athletic population, but can also occur in older individuals who may have some pre-existing arthritis or degeneration in the knee. In the latter situation, the damage can be caused by less forceful twisting movements. As we age, the flexibility of the meniscus decreases and it becomes less able to withstand force. Individuals who have had previous injuries to the knee, or have had a lot of wear and tear to the knee, may be more at risk of developing early arthritis and degeneration of the knee and menisci.
Symptoms of a meniscus injury can include:
- Sudden onset pain, which is associated with “giving out” of the joint
- Locking of the knee when the leg is straightened or fully bent
- Intermittent buckling and clicking in the knee
- Ongoing or intermittent swelling around the joint
- Decreased ability to put weight on the le
What Can You Do?
After any knee injury you should see a physiotherapist for an assessment and a full program of rehabilitation. The program will be prescribed according to your particular injury and symptoms, and progressed as your symptoms decrease and your knee gets stronger.
At Saanichton Physiotherapy and Sports Clinic, your physiotherapist will work in conjunction with your physician or specialist to put you on the most optimal rehab program. Your therapy may include:
- Exercises to strengthen, stretch and maximize the range of motion of your knee
- Balance training (known as proprioception exercises) to improve the stability of the joint
- Hands-on manual therapy techniques
- Ultrasound and electric modalities to decrease pain and swelling
- Advice on a brace, walking aids, and return to sports