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Knee osteoarthritis

Find out how knee osteoarthritis is diagnosed and treated

Osteoarthritis is a type of arthritis. It is the most common type of arthritis in the UK, affecting nearly 9 million people. Osteoarthritis is more common in women and those who in are their mid-40s or older, but it can occur at any age as the result of injury.  

Knee osteoarthritis affects the smooth cartilage that lines the knee joints. The process of osteoarthritis involves wearing or thinning of the smooth cartilage joint surfaces as well as stiffening to the soft tissue surrounding the joint.  

Arthritis in knee makes the movement of the affected joint more difficult, which leads to pain and stiffness. It can also lead to the formation of bone spurs in the knee.  

The condition is most commonly caused by age. However, several factors normally combine to cause the symptoms of knee osteoarthritis. These include:

  • Previous joint damage
  • Increased bodyweight
  • Age (risk increases with age)
  • Family history (genetics)
  • Poor lower limb alignment (this is called biomechanics)

General exercise such as walking, cycling and playing sport does not increase the risk of developing or increase the rate of deterioration of knee osteoarthritis.

Knee osteoarthritis can be usually be diagnosed by an orthopedic surgeon by looking at the history of your condition. A physical examination may help to assess the severity of the damaged joint.

The main feature on examination is often a painful reduction in the range of movement. There is often weakness of the thigh muscles and there may be a deviation of the normal alignment of the knee. This can be associated with a grinding (crepitus) sound.

The knee joint may become swollen as a result of the inflammatory change (synovitis) within the joint. On occasions, the fluid will cause swelling at the back of the knee. This is sometimes called a Baker’s cyst. This is not serious and will often resolve as the swelling goes down. If this swelling becomes more painful and inflamed, then you should seek medical attention.

Osteoarthritis knee x-rays are not routinely required but may be requested if symptoms are severe enough that total knee replacement surgery is being considered.

The main symptoms of knee osteoarthritis include:

Joint pain, particularly when walking as it is the main aggravating activity.

  • Tenderness of the joint.
  • Osteoarthritis knee swelling
  • Limited range of movement in the knee joint.

Osteoarthritis knee pain will normally be felt adjacent to the affected part of the knee. Knee osteoarthritis can occur in the following areas:

  • the outer part of the knee (lateral compartment)
  • the inner part of the knee (medial compartment)
  • under the knee cap (patellofemoral joint)
  • a combination of all three.

You may also experience referred pain, which radiates into the shin or calf muscle.

If knee osteoarthritis becomes more severe, the movements of the knee may become increasingly stiff. This may cause an associated instability and giving way of the knee joint.

The presence of knee osteoarthritis does not always cause pain so it is possible to be pain-free despite reasonably advanced arthritis. In addition, the knee undergoes a wear-and-repair cycle so pain can improve with time and appropriate management.

In the majority of cases, the symptoms of knee osteoarthritis can be managed effectively by non-surgical measures as described below. The most effective are exercises and weight loss for those who are overweight. Over-the-counter medication can be taken for pain relief.

Weight loss

Losing weight reduces the load on your joints as you move about. Evidence shows that weight loss can result in significantly better mobility. There is also some evidence to suggest that weight loss alone may actually relieve the pain. However, in combination with exercise, the results can be staggering.

You can use a Body Mass Index (BMI) calculator, which will tell you if it is advisable for you to try to lose some weight.

Physiotherapy exercises for knee osteoarthritis  

Regular exercises will help you to maintain flexibility and strengthen the affected knee joint.

Suggested osteoarthritis knee exercises include:

Standing quads stretch with posterior tilt

In each exercise, perform the five stretches for 30 seconds each. This exercise should be performed twice a day.

Inner Range Quadriceps (IRQ) with weight

In each exercise, perform three to four sets of 10 reps each. This exercise should be performed three to four times a week.

Sit to stand

In each exercise, perform three to four sets of 10 reps each. This exercise should be performed three to four times a week.

Your physiotherapist may advise wearing a knee brace for osteoarthritis when exercising. This is to provide support for the knee joint. The therapist will discuss with you the types of knee braces and highlight which type of brace is most suitable for you.

Use painkillers when needed

Over-the-counter pain medication is available through your local pharmacy when needed. Paracetamol is most commonly prescribed. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as Ibuprofen, are also used, but as there is little or no inflammation involved in osteoarthritis these are best avoided without discussing with your doctor.

Side effects are even more common than with paracetamol so please ensure to take appropriate medical advice. There is a good booklet on the Arthritis Research UK website with information about the various drug options.

APOS Therapy trial

For patients with advanced osteoarthritis who want to avoid surgery, APOS Therapy may provide a treatment option. It is based around a shoe-like biomechanical device that can help to distribute the forces more evenly through the joint and aid in strengthening the knee. Please note this service is only currently available for Bedfordshire patients.

Corticosteroid injection therapy

A course of corticosteroid injections may be offered for individuals with mild to moderate knee osteoarthritis.

These may also be an option for those patients who continue to suffer disabling symptoms despite following a course of non-surgical management of the condition. Or that the knee strengthening exercises for osteoarthritis have not shown any improvement in the reduction of pain.

Knee injections for osteoarthritis may also be suitable for patients who are unable to commence a supervised exercise program due to pain levels.

Osteoarthritis knee surgery

Total knee replacement surgery is an effective option for patients with advanced-stage knee osteoarthritis. To be considered for surgery, you normally need to pass the following criteria:

  • Have trialled a course of non-surgical management without success
  • Have consistent, disabling pain significantly limiting mobility or affecting sleep pattern
  • Have a satisfactory Body Mass Index (BMI) or if BMI of more than 35 have made lifestyle changes to lose excess bodyweight

You may be asked to complete a questionnaire called an Oxford Knee score. This can help the clinician assess the impact of your symptoms which can be useful in assessing suitability for surgery.

Further information about living with osteoarthritis of the knee, visit Arthritis Research UK.

Specialists offering Knee osteoarthritis

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Mr Rishi Chana

Consultant Hip and Knee Orthopaedic Surgeon

MBBS, BSc (Hons), MRCS Ed, MSc (Dist), PG Med Ed, FRCS Tr&Orth Ed

The Chiltern Hospital 1 more The Princess Margaret Hospital

View profile Book online

Mr Bhupinder Singh Mann

Consultant Orthopaedic Surgeon

BSc, MBBS, MRCS, FRCS, (Tr. & Orth.)

The Chiltern Hospital 1 more The Shelburne Hospital

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Mr Parm Johal

Consultant Orthopaedic Surgeon

MBBS, MD, FRCS(Tr & Orth)

The Chiltern Hospital

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Mr David Johnstone

Consultant Orthopaedic Surgeon

MBBS, FRCS England, FRCS (Orth.)

The Chiltern Hospital

View profile Book online

Mr Nick Beattie

Consultant Orthopaedic Surgeon

BSc (Hons.), MBCHB, MRCS, FRCS(Ed) T+O, PG Cert Ed

The Chiltern Hospital 1 more The Shelburne Hospital

View profile Book online

Mr David Houlihan-Burne

Consultant Orthopaedic Surgeon

BSc (Hons), MB BS (Hons), MRCS, FRCS (Orth)

Bishops Wood Hospital 1 more The Chiltern Hospital

View profile Book online

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