The Knee

The ends of our joint surfaces are lined with articular cartilage. This cartilage is made up of small cells called chondrocytes, along with a combination of proteins, collagen, and lots of water. In healthy joints, this durable cartilage allows joint surfaces to move against one another with minimal friction. Cartilage also acts as a shock absorber, by facilitating the transmission of loads to the underlying (subchondral) bone.

Losing cartilage in certain areas can often interfere with the normal movement of joints and limbs. This can result in pain and being less able to carry out regular daily or sporting activities.

In some cases it may be possible for us to fill missing sections with new cartilage which provides new protection for the joint surface. However, in cases where there are more extensive areas of missing or damaged cartilage there is an increased likelihood of arthritis and other management options may have to be explored.

The meniscus plays a role in joint stability, as well as load distribution. Tears in the meniscus are common, and often happen because of an acute injury.

Meniscal tears are often treated by removing a piece of the torn meniscus, which is called a partial meniscectomy, which may make the joint more vulnerable to degeneration of the articular cartilage.

Some meniscal injuries can be repaired via key-hole surgery (arthroscopically), where the torn piece(s) of the meniscus are sutured / stitched back together. This depends on the type of tear, as well as the overall status of the damaged meniscus and age of patient. Unfortunately due to the relatively poor blood supply of the menisci, many tears are not suitable for repair.

Anterior Cruciate Ligament (ACL)

The ACL is important in controlling rotation of the knee, during lateral, multi-directional and landing movements, and is one of the most commonly injured structures among athletes.

Typical symptoms of an ACL injury include:

• An audible “popping” sensation within the knee
• Swelling
• Pain
• A feeling of instability like the knee may “give way”
• Stiffness / loss of full range of motion

Treatment options for ACL injury can vary depending on a person’s specific needs.

Reconstructive surgery is often recommended to restore stability of the knee required for multi-directional movement or sport. However for people with a lower level of activity, less invasive measures such as rehabilitation and / or bracing of the knee may be more suitable.

As the ACL cannot usually be repaired, restoring a torn ACL through surgery involves replacing the ACL with a piece of tissue taken from another part of the leg (a graft), such as from the patellar tendon or the hamstring. Other graft options are also sometimes considered.

Posterior Cruciate Ligament (PCL)

The PCL prevents the tibia from sliding backwards too much, and also helps stabilise the knee in rotational movements.

Injuries to the PCL are generally the result of a direct blow to the front of the knee, when the leg is in a bent position, (such as falling on a bent knee). PCL injuries can also occur when the knee twists or straightens too much (hyperextends).

Isolated PCL injuries generally do not cause instability. A large amount of instability may mean there is a PCL injury combined with an injury to another specific section of the knee called the posterolateral corner.

Treatment depends on how severe the injury is, and whether it is an isolated or combined injury. Rehabilitation is a vital component of recovery in both surgical and conservative cases.

Medial Collateral Ligament (MCL)

Lateral Collateral Ligament (LCL)

Patellofemoral Pain

Patellofemoral pain is a broad term used to describe pain at the front of the knee.

There are various factors that contribute to patellofemoral pain, both internal and external to the knee, including malalignment. However, the main risk factors appear to be overuse and overload.

Management of the injury requires a multi-faceted approach. Particular emphasis is placed on load management, along with a structured rehabilitation programme to strengthen the surrounding muscles as well as addressing abnormal movement patterns.

Patellar Instability

The kneecap (patella) sits in a notch on the femur bone called the trochlea. If this groove is too shallow, the patella can become unstable and slide off, resulting in a partial or complete dislocation of the kneecap.

Dislocation can also occur during an acute injury such as a fall, or a rotational type injury of the knee.

Patients with a high riding patella that sits above the groove and patients with other anatomical variants are also more prone to dislocation.

If the patella becomes dislocated, it needs to be relocated or “reduced”, which often happens spontaneously. If the instability keeps reoccurring, surgery may be needed to stabilise the patella, followed by a rehabilitation programme to strengthen the soft tissue structures of the knee, and to prevent any further dislocations.

Patellar Fractures

Fractures to the patella bone usually happen because of a fall or hard blow to the front of the knee.

Treatment options for this type of injury depend on the type of fracture. An undisplaced fracture of the patella, where the broken bone remains in the correct place, generally responds well to being immobilised in a knee brace or cast. Displaced fractures often require surgical treatment to stabilise the site of the fractured bone.

Both conservative and surgical treatments need to be complemented with a rehabilitation programme to strengthen the muscles around the knee.

Proper knee alignment is essential for normal function and for balance in the joint. Poor movement patterns which cause uneven forces throughout the knee can damage both its articular cartilage and ligaments.

There are two types of misalignment in the knee, which can contribute to its condition:

• Knee varus where the weight passes medially, (more through the inside of the knee joint), causing degeneration to the inside of the knee
• Knee valgus where the weight passes laterally, (more to the outside of the knee joint) causing degeneration to the outside of the knee

A corrective surgical procedure called an osteotomy redistributes the forces bearing down on the knee by cutting a wedge of bone from either the tibia or femur, to reposition and realign the knee.

Osteoarthritis is the most common form of arthritis, and often affects the knee joint.

Osteoarthritis is caused by aging and wear and tear of cartilage. Symptoms of osteoarthritis in the knee may include knee pain, stiffness, and swelling.

Knee Replacement

If the degree of osteoarthritis is quite severe and debilitating, a Total Knee Arthroplasty is often the recommended form of treatment.

This open procedure involves removing the damaged areas of cartilage loss, and replacing them with synthetic components (often metal), to recreate the joint surfaces. The inner surface of the patella may also be resurfaced if needed. An artificial “spacer” is inserted between the metal components to allow the new joint to glide smoothly and efficiently.

We carry out an orthopaedic evaluation of your knee through the following three activities:

• A medical history to gather information about current complaints, duration of symptoms, pain and limitations, injuries, and past treatment with medications or surgery.
• A physical examination to assess swelling, tenderness, range of motion, strength, instability, and limb alignment.
• Diagnostic tests, such as X-rays or magnetic resonance imaging (MRI), which may be required to assess both the bony and soft-tissue structures of the knee.

We will discuss the results of your orthopaedic evaluation and the various treatment options available to you in detail.

Arthroscopy

Arthroscopic surgery is when the surgeon inserts a thin, pencil-sized device, containing a tiny lens and lighting system, into a small incision to look inside the knee joint. The images inside the joint are shown on a TV monitor and allow the surgeon to make a clear diagnosis.

Other surgical instruments can also be inserted so that repairs can be made, depending on the diagnosis.

Surgeries such as a partial meniscectomy, meniscal repair, or ACL reconstruction, are generally carried out using these arthroscopic methods.

Open Surgery

Knee replacement is an open surgery performed through an incision at the front of the knee. Other surgeries such as collateral ligament reconstruction and osteotomy are also performed by open incisions to the knee of varying lengths and location depending on the specific procedure.

Rehabilitation is crucial to maximise the success of any knee surgery, and commitment to a structured rehab programme is an essential part of your recovery.

This rehabilitation should be closely followed in consultation with your orthopaedic surgeon and chartered physiotherapist.

Click the following link to download this brochure SSC The Knee