Knee Arthritis

Technical Name: Osteoarthritis (OA) of the knee

AKA Name: Knee arthritis

Short Summary:

The knee joint is the articulation between two main bones - the femur (thigh bone) and the tibia (the shin bone).  In front of the knee the patella (knee cap) runs in a groove on the end of the thigh bone as the knee bends and straightens.  Joint surface cartilage (or articular cartilage) covers the ends of the bones - a low friction robust covering, several millimetres thick - which enables the joint to move smoothly and acts as a shock absorber.  Within the knee joint there are also separate cartilage pads (menisci) that give further cushioning and help to stabilize the joint.  These are crescent shape structures that run around the inner (medial) and outer (lateral) aspects of the knee.    

What is osteoarthritis?

Osteoarthritis describes the wear and tear degeneration of the joint cartilage lining the bone surface (osteo meaning bone and arthritis meaning painful inflammation of joints).  Cartilage has no nerve endings, but when this covering wears away it exposes the underlying bone surface that is very sensitive to pressure (bone on bone). 

Osteoarthritis tends to affect middle to older-age patients as a result of the wearing process but can affect younger people, especially if those individuals have suffered a significant injury or trauma to the knee e.g. cruciate ligament rupture, or have a strong family history of arthritis.

Most commonly the inner (medial) aspect of the knee wears out more than the outer (lateral) aspect and the knee cap (patella-femoral joint).  This is why patients with arthritis of the knee can develop bow legs.

What are the symptoms?

Knee arthritis (osteoarthritis) commonly presents with increasing pain, stiffness and swelling around the knee.  It tends to become noticeable initially with activity but then can progress to experiencing pain at rest (and at night) as the arthritis worsens.   

At worst, pain and loss of function in the knee can have a significant impact on an individual’s quality of life such that even simple short walks can be difficult or you are now thinking of stopping hobbies that you previously enjoyed.

As the knee joint moves it can ‘creak’ and ‘crunch’ (crepitus) that can indicate arthritis but this can occur in healthy knee joints also. 

How is it diagnosed?

A diagnosis of arthritis is made following a through medical consultation (history and examination) followed by an x-ray to confirm the findings.

The x-ray will demonstrate the extent of the joint cartilage wear within the knee joint. Sometimes it may be necessary to undergo an MRI scan to gain more information about the knee.

How is it treated?

Many patients have early-stage arthritis and function to a high level with little impact on their quality of life.  However when this balance changes and the symptoms are become intrusive on your quality of life then this is the stage when treatment options can be considered:

  • Non operative treatments include 
    • Weight loss helps reduce the load through the knee and reduces progression of any damage already present
    • Physiotherapy to maintain muscle strength and range of movement
    • Pain killers including paracetamol and anti-inflammatories
    • Injections into the knee of local anaesthetic and steroids as well as visco-supplementation (artificial joint fluid) in some cases 
  • Operative treatments (surgery) are considered when patients’ symptoms become highly intrusive in their everyday life, x-ray findings show arthritis and other treatment options have been tried or are unlikely to be effective.
    • Total Knee Replacement (TKR) replaces all three compartments within the knee and consists of both metal and plastic components
    • Partial (Unicompartmental) Knee Replacement (PKR/UKR) resurfaces only the affected compartment within the knee if the process is more isolated

Important: this information given above is only a guideline as is not complete.  For more information or to book an appointment please contact us.