When is surgery considered for knee arthritis?

Understanding knee arthritis

Knee arthritis is one of the most common causes of knee pain and stiffness, particularly as we get older. It occurs when the smooth cartilage that lines and cushions the joint becomes damaged and gradually thins, leading to pain, swelling, and loss of function.

Although arthritis is often associated with age, it is not simply a “wear and tear” condition. Modern research shows that osteoarthritis is a complex process involving mechanical, biological, and inflammatory changes that affect the entire joint—not just the cartilage.

Why osteoarthritis develops

Osteoarthritis develops when the normal balance between cartilage breakdown and repair becomes disrupted. Over time, this leads to thinning of the cartilage surface, but the process is influenced by several factors:

• Mechanical factors such as previous injury, altered leg alignment, or repetitive loading that changes how pressure is distributed through the knee.
• Biological and inflammatory changes affecting the joint lining (synovium), bone, and cartilage cells, leading to gradual deterioration and pain.
• Systemic influences such as age, genetics, body weight, and metabolic or hormonal factors, which can make joints more prone to arthritis.

Ultimately, the cartilage does thin, but this is the end result of a more complex process. Understanding osteoarthritis in this way helps explain why symptoms vary widely between people, and why a combination of lifestyle, medical, and occasionally surgical treatments are effective in managing it.

Symptoms of knee arthritis

Symptoms can develop gradually and often fluctuate in intensity. Common features include:

·      Pain during or after activity

·      Night pain, which may disturb sleep

·      Stiffness after periods of rest or first thing in the morning

·      Swelling or warmth around the knee

·      Grinding, catching, or a sensation of the knee giving way

A detailed history, examination, and imaging (usually X-rays) help confirm the diagnosis and guide treatment.

Managing knee arthritis without surgery

Many people can manage their knee arthritis effectively without needing surgery. There are a wide range of non-operative measures that can significantly improve pain and function, even though they cannot reverse the underlying arthritis.

These include:

·      Pain relief and anti-inflammatory medication (if suitable)

·      Topical gels or rubs for targeted symptom control

·      Physiotherapy to improve strength and joint mobility

·      Activity and lifestyle modification, such as switching to low-impact exercise

·      Weight management, which can greatly reduce joint load and discomfort

·      Walking aids or braces, to provide support and offload pressure from the affected area

·      Injections, including corticosteroid or hyaluronic acid in selected cases

In most cases, these treatments help make symptoms more tolerable and allow patients to stay active. Surgery is only considered when pain and stiffness continue to have a major impact on quality of life despite appropriate non-operative care.

When surgery becomes an option

If non-surgical measures no longer provide sufficient relief, and daily activities are significantly affected, knee replacement surgery may be recommended. This is a very successful operation with a high rate of patient satisfaction and excellent long-term outcomes.

There are two main surgical options:

1. Partial (unicompartmental) knee replacement – suitable when arthritis is confined to one part of the knee. This procedure replaces only the affected part of the joint, leaving the remainder of the knee and the ligaments intact. Recovery is often quicker, and the knee can feel more natural, though there is a small chance that further surgery may be needed if arthritis develops in other areas of the joint.
2. Total knee replacement – performed when arthritis affects most or all of the joint. The damaged surfaces are precisely removed and replaced with smooth metal and high-grade plastic components that restore alignment and movement.

During surgery, the damaged joint surfaces are removed and replaced with the artificial components, which are fixed securely to the bone using orthopaedic cement. The new joint is checked for stability and range of motion before the wound is closed.

Rehabilitation and recovery

Most patients are encouraged to walk with physiotherapy support within 24 hours of surgery. Early movement helps prevent stiffness and promotes recovery. Exercises are a crucial part of rehabilitation, and consistency is key to achieving a good range of motion and long-term function.

Pain and swelling gradually improve over several weeks, and most patients return to everyday activities within a few months. Around 90% of patients feel significantly better following knee replacement surgery, and modern implants have excellent long-term survival, with around 95% lasting at least 15 years.

In summary

Knee arthritis is not just a product of age or wear - it’s a complex process affecting the whole joint. The good news is that there are many ways to manage symptoms effectively. With the right balance of non-operative treatment and, where appropriate, surgery, most people can achieve excellent pain relief and return to an active lifestyle.