The knee is subject to a great deal of torque and forces in our daily lives. It must be able to support the entire body weight for single leg stance during walking/running and has to allow for squatting/sitting activities (both of which require a large range of motion).
The knee is vulnerable to many injuries, and often diagnosis of a knee problem involves x-rays, MRIs, and hands-on assessment. Because of their proximity, problems of the knee and hip are often related. A hip disorder may cause knee pain, and knee disorders can aggravate hip problems.
Treatment of the knee will be based on your primary problem and will include:
- A pain relief program and patient education on the knee (including its anatomy, risk factors for pain, and ways to manage pain in the short term at home)
- Assessment of other joints/driving factors (leg length, gait, pelvic alignment, hip and ankle motion, etc)
- Development of a home treatment program to speed recovery
- Manual therapy (massage and hands-on stretching) to normalize range of motion and muscle tone
- Exercise to improve movement and strength
- Balance training and conditioning as needed
Some common conditions of the knee:Arthritis: describes the degenerative condition where cartilage within the joint breaks down leading to less cushion and more friction in the joint. Arthritis of the knee is fairly common and typically affects people beginning in middle age, however studies have recently shown that it can be present in the younger population if previous knee trauma has occurred. Often arthritis is related to cartilage damage (meniscus tear), prior fracture, and overuse (athletics, prolonged standing/walking over a lifetime). In severe cases, a total knee arthrosis (aka TKA) may be recommended (see TKA – see below).
While arthritis is incurable, many of the secondary symptoms that accompany it (pain, weakness, muscle tightness/spasm, and inflammation) can be managed by physical therapy.
Some symptoms of knee arthritis may include:
- Stiffness/pain in the knee that is worse after prolonged periods of rest
- Grinding/crunching in the knee that is also painful
- A dull ache after prolonged use of the knee (walking, standing) that ends with increased stiffness
- A loss of extension/flexion motion of the knee (inability to fully straighten or bend the knee)
TKA: Stands for “total knee arthrosis, “ formerly known as a total knee replacement. This procedure involves replacement of the knee joint (tibiofemoral and patellofemoral) with an internal metal prosthetic. After a TKA, the surgeon will likely prescribe physical therapy to improve range of motion and flexibility, improve strength, decrease inflammation and manage scar healing, and improve gait and activities of daily living.
Meniscal tears: As mentioned above, the meniscus is a “C”-shaped piece of cartilage that sits between the femur and tibia to make the knee joint more congruent, and thus more stable. In each knee there are two menisci, one medially (on the inside of the knee) and one laterally (on the outside of the knee). Each meniscus has an inner component (avascular, meaning no blood flow) and an outer component (vascular, with blood flow from the surface capillaries). Because of its lack of blood flow, the inner portion of the meniscus, once torn, is often surgically removed (it cannot heal without a blood supply). The outer portion of the meniscus, once torn, can be surgically repaired.
Meniscus tears occur with twisting and sudden bending motions of the knee. They are common in younger athletes, but can happen in adults during daily activities because of a loss of strength and overall deconditioning.
Whether or not your surgeon feels that surgery is necessary (some tears are left alone), they will likely prescribe physical therapy to address your pain get you back to your normal activities.
Symptoms of a meniscus tear include:
- Pain along the joint lines of the knee
- “Clicking” or “popping” with bending/extending the knee – may or may not be painful
- a “locking” sensation at certain ranges of motion
- swelling/possible bruising along the knee initially
That said, ACL injury risk can be minimized by training and strengthening the muscles in the leg, and many athletic programs and physical therapy clinics have workout protocols to do just that.
Symptoms of an ACL tear may include:
- pain and a feeling of instability in the knee after trauma
- a “shifting” sensation with squatting
- muscle weakness and balance deficits within the first few weeks after injury
Physical therapy is often prescribed for ACL tears both before and after surgery, or in place of surgery in certain patients. Treatment involves regaining range of motion, increasing strength, improving balance, and re-educating the leg muscles to prevent re-injury.
Anterior knee pain: is a common complaint and occurs in all types of patients. Often the onset of anterior knee pain is insidious (without distinct injury) and many times the condition is related to overuse. Some diagnoses associated with anterior knee pain include:
PFPS: or patello-femoral pain syndrome, occurs when there is swelling under the kneecap, the kneecap tracks poorly (moves out of proper alignment), and there is excess stress on the patellar tendon. Often this condition is associated with patellar tendonitis (inflammation of the patellar tendon).
Symptoms may include:
- a clicking/grinding under the kneecap with bending/straightening the knee
- pain with walking, running, or going up and down stairs
- an inability to kneel on that side due to pain
Pes anserine tendonitis: the pes anserine is located on the inside of the knee, just below the joint. It is the attachment point for three muscles of the hip/thigh and can become inflamed with overuse. There is a bursa located in this area, and inflammation of the pes anserine tendon may also cause bursitis (the bursa is an easy place for swelling to collect).
Symptoms may include:
- tenderness/swelling along the pes anserine
- pain if the knees touch (as when sleeping)
- aching pain in the medial knee and some radiating pain into the inside of the shin
Osgood-Schlater’s disease: occurs in children and adolescents because their bones are not yet fully formed and are still softer. It is an irritation of the tibial tuberosity (the prominent bump at the top of the shin). This is where the patellar tendon attaches. In children that perform a great deal of running/jumping (gymnasts, soccer players, football players, etc) the quadriceps muscle pulls on the patellar tendon and the force irritates the growing bone. The tibial tuberosity will become enlarged and swollen.
Symptoms may include:
- tenderness to the touch over the top of the shin
- visible swelling
- pain with activities such as going up and down stairs, running, and jumping
ITBS: or iliotibial band syndrome is an irritation of the IT band. The IT band originates on the gluteal muscles/hip and runs down the outside of the thigh to the knee. It is a very thick, very tough piece of connective tissue that helps anchor some of the muscles in the lower leg and gives us more strength through the hip when walking/running. At the knee it crosses over several bony prominences that, if it is tight, will cause irritation. ITBS is very common in runners.
Symptoms may include:
- pain in the knee (along the outside at the end of the thigh) with the last few degrees of extension
- pain with running: more so at the beginning and end of the run
- tenderness to the touch
- visible swelling along the outside of the knee joint
Baker’s Cyst: is a fluid-filled cyst that causes a bulge and a feeling of tightness behind your knee. The pain can get worse when you fully bend or straighten your knee or when you're active.
A Baker's cyst, also called a popliteal cyst, is usually the result of a problem with your knee joint, such as arthritis or a meniscus tear (see above). Both conditions can cause your knee to produce too much fluid, which can lead to a Baker's cyst. Although a Baker's cyst may cause swelling and make you uncomfortable, treating the underlying problem usually provides relief. Your physical therapy assessment will include a thorough screening to diagnose the underlying problem.
Patellar subluxation/dislocation: occurs when the kneecap leaves the groove of the femur that it is seated in (if it returns on its own this is subluxation; if it stays our of place this is dislocation). This can occur with trauma, loose ligaments (“double jointed”), and if there is excess swelling under the patella.
Symptoms may include:
- severe pain and an inability to move the knee
- visible deformation (if dislocation) of the front of the knee (the kneecap is in the wrong place)
- significant swelling and extreme tenderness to the touch (if dislocation)