What is knee arthritis?

Knee arthritis is a condition characterized by a degenerative process whereby there is gradual wear and tear to the cartilage and bone surfaces of the knee joint with subsequent inflammation. Knee arthritis may occur following a specific injury or due to repetitive forces going through the knee joint beyond what it can withstand over a period of time.

In a normal knee, joint surfaces are smooth and there is cartilage between the bone ends which allows for efficient shock absorption and smooth movement (figure 1).

Figure 1 - Relevant Anatomy for Knee Arthritis

When the knee is damaged or overloaded, particularly with excessive weight-bearing or twisting forces, degeneration of the cartilage can occur, reducing the knee's shock absorbing capacity. As the condition progresses, and the cartilage wears away, the joint space can narrow and there is eventual wearing down of the bone ends so that the surfaces are no longer smooth (figure 2). The bone ends may also develop small bony processes (spurs) called 'osteophytes'. When some or all of these changes occur, the condition is known as knee arthritis.  

Figure 2 - An X-ray Demonstrating Knee Arthritis

Arthritis of the knee usually occurs after the age of 50 years and tends to affect females more frequently than males. It is more common in those patients who are overweight or have a past history of injury, surgery or trauma to the knee.

---

Signs and symptoms of knee arthritis

Patients with this condition usually experience symptoms that develop gradually over time. In patients with minor cases of knee arthritis, little or no symptoms may be present. As the condition progresses, there may be increasing knee pain with weight bearing activity and joint stiffness (particularly after rest or first thing in the morning). Swelling, decreased flexibility (i.e. an inability to fully straighten or bend the knee), severe joint pain, pain at night and a grinding, clicking or locking sensation during certain movements may also be experienced. Symptoms can sometimes fluctuate from month to month with patients reporting an increase in symptoms with colder weather. In more severe cases, muscle wasting (especially of the quadriceps), a visible deformity of the knee joint, and a limp may also be present.

---

Diagnosis of knee arthritis

A thorough subjective and objective examination from a physiotherapist may be sufficient to diagnose knee arthritis. An X-ray is usually required to confirm diagnosis and may demonstrate signs of decreased joint space, irregularities of the bony ends and/or the presence of bony spurs (osteophytes). Sometimes an MRI may also be indicated to assist with diagnosis and rule out other pathologies.

---

Prognosis of knee arthritis

Because arthritis of the knee is a progressive condition, complete resolution of symptoms is often not possible. However, in mild to moderate cases, most patients, if managed well, can maintain an active lifestyle with little or no symptoms and delay or prevent the deterioration of the condition. In severe cases that have been unresponsive to appropriate physiotherapy management and where quality of life is significantly affected, knee joint replacement surgery is usually indicated with most patients subsequently experiencing a good outcome following the procedure.

---

Physiotherapy for knee arthritis

For detailed information on physiotherapy treatment of this condition Become a Member.

Already a Member?

 

View the complete article - Knee Arthritis (Members Only).

---

Contributing factors to the development of knee arthritis

For detailed information on factors contributing to the development of this condition Become a Member.

Already a Member?

 

View the complete article - Knee Arthritis (Members Only).

---

Other intervention for knee arthritis

Despite appropriate physiotherapy management, some patients with arthritis of the knee continue to deteriorate. When this occurs, other intervention may be required. This may include pharmaceutical intervention, corticosteroid injection, the use of supplements such as fish oil, glucosamine and chondroitin, investigations such as an X-ray, CT scan, bone scan or MRI, or assessment from a specialist.

In more advanced cases of knee arthritis, where symptoms are severe and quality of life severely affected, patients may require surgical intervention. This may involve a knee arthroscope or partial or complete knee joint replacement surgery. The treating physiotherapist or doctor can advise if this may be required and will refer to an orthopaedic specialist for an assessment and opinion.

Following a total knee joint replacement, patients are normally in hospital for 5 to 10 days afterwards and require physiotherapy treatment and rehabilitation over the following months. Resumption of normal daily activity can usually be achieved 6 – 12 months following surgery.

---

Exercises for knee arthritis

The following exercises are commonly prescribed to patients with arthritis of the knee. You should discuss the suitability of these exercises with your physiotherapist prior to beginning them. Generally, they should be performed 3 times daily once the physiotherapist has indicated it is safe to do so and only provided they do not cause or increase symptoms.

Your physiotherapist can advise when it is appropriate to begin the initial exercises and eventually progress to the intermediate and advanced exercises. As a general rule, addition of exercises or progression to more advanced exercises should take place provided there is no increase in symptoms.

---

Initial Exercises

Knee Bend to Straighten 

Lying on your back, slowly bend and straighten your knee as far as you can go without pain and provided you feel no more than a mild to moderate stretch (figure 3). Repeat 10 times. 

Figure 3 – Knee Bend to Straighten (right leg)

Static Quadriceps Contraction 

With your knee relatively straight, slowly tighten the muscle at the front of your thigh (quadriceps) by pushing your knee down into a small rolled up towel (figure 4). Put your fingers on your quadriceps to feel the muscle tighten during the contraction. Hold for 5 seconds and repeat 10 times as firmly as possible without increasing your symptoms.

Figure 4 – Static Quadriceps Contraction (left leg)