Knee Arthritis & Knee Replacement

Knee arthritis is one of the most common causes of knee pain, stiffness and reduced mobility. Many patients improve with non-surgical treatment. However, when pain begins to affect walking, sleep or quality of life, knee replacement surgery may provide excellent pain relief and restore function.


What is Knee Arthritis?

The knee joint is formed by the femur (thigh bone), tibia (shin bone) and patella (kneecap). These joint surfaces are normally covered by smooth cartilage, allowing painless movement.

Knee arthritis develops when this cartilage gradually wears away. As the cartilage deteriorates, the bones begin to rub together, resulting in pain, stiffness, swelling and reduced movement.

The most common causes include:

  • Osteoarthritis

  • Rheumatoid arthritis

  • Previous knee injury

  • Post-traumatic arthritis

  • Inflammatory arthritis


Symptoms of Knee Arthritis

Symptoms commonly include:

  • Knee pain during walking

  • Pain when climbing stairs

  • Stiffness after sitting

  • Swelling

  • Grinding or clicking

  • Difficulty walking longer distances

  • Knee deformity

  • Night pain

Many patients notice their symptoms gradually worsen over several years.


Diagnosis

Knee arthritis is usually diagnosed through your history, examination and X-rays.

X-rays typically demonstrate narrowing of the joint space, bone spurs and loss of cartilage.

Occasionally, further imaging such as MRI or CT scanning may be recommended for surgical planning or to investigate other causes of knee pain.


Non-Surgical Treatment

Many patients experience significant improvement without surgery.

Treatment options may include:

  • Physiotherapy

  • Activity modification

  • Weight management

  • Anti-inflammatory medication

  • Simple pain relief

  • Walking aids where appropriate

  • Corticosteroid injections

These treatments help reduce pain and improve function but do not reverse arthritis.


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Knee Replacement Surgery

When pain persists despite appropriate non-surgical treatment, knee replacement surgery may be recommended.

Depending on the pattern and severity of arthritis, treatment may involve either:

  • Partial knee replacement

  • Total knee replacement

The most appropriate procedure depends on which parts of the knee are affected, your age, activity level and overall health.


Partial Knee Replacement

Partial (unicompartmental) knee replacement replaces only the damaged portion of the knee while preserving healthy cartilage, ligaments and bone.

It may be appropriate when arthritis is confined to one compartment of the knee.

Potential benefits include:

  • Smaller operation

  • Faster recovery

  • More natural-feeling knee

  • Better range of movement

  • Less disruption of normal anatomy

Not every patient is suitable for a partial knee replacement.


Total Knee Replacement

Total knee replacement replaces the worn surfaces of the knee with artificial metal and polyethylene components.

It is most commonly recommended for patients with widespread arthritis affecting multiple compartments of the knee.

Benefits include:

  • Excellent pain relief

  • Improved walking

  • Improved quality of life

  • Reliable long-term outcomes

Modern total knee replacement is one of the most successful procedures in orthopaedic surgery.


Robotic & Computer-Assisted Knee Replacement

Modern technology has transformed knee replacement surgery.

Where appropriate, robotic and computer-assisted technology may be utilised to improve implant positioning, alignment and restoration of normal knee mechanics.

These technologies assist surgical planning and precision, allowing treatment to be tailored to each patient's unique anatomy.


Recovery After Knee Replacement

Recovery varies between individuals, however most patients can expect:

  • Walking on the day of surgery or the following day

  • A short hospital stay

  • Early physiotherapy

  • Progressive strengthening

  • Gradual return to everyday activities

  • Continued improvement for up to 12 months

Rehabilitation is an important part of achieving the best possible outcome following knee replacement.


Frequently Asked Questions

Do I need a knee replacement?

Not necessarily. Many patients successfully manage knee arthritis with physiotherapy, exercise, medications and injections before surgery becomes necessary.

What is the difference between partial and total knee replacement?

Partial knee replacement treats arthritis affecting one part of the knee while preserving healthy structures.

Total knee replacement treats arthritis involving the whole knee.

Is robotic knee replacement better?

Robotic and computer-assisted technologies improve surgical planning and precision. Whether they are appropriate depends on your individual condition and treatment goals.

How long does a knee replacement last?

Modern knee replacements are designed to provide many years of reliable function, although longevity varies according to activity level, age and overall health.



Why Choose Peak Orthopaedics?

Mr Francis Ting is a fellowship-trained orthopaedic surgeon with experience in hip and knee replacement surgery.

Using contemporary techniques, robotic and computer-assisted technology where appropriate, and evidence-based rehabilitation, treatment is tailored to each patient's individual anatomy, lifestyle and goals. Whether treatment involves physiotherapy, partial knee replacement or total knee replacement, the aim is to relieve pain, restore movement and help patients return to the activities that matter most.


Referral Information

Peak Orthopaedics provides specialist assessment and hip replacement surgery for patients throughout New Plymouth and the wider Taranaki region.

Patients are typically referred by their GP, physiotherapist or another healthcare professional. Referral is generally required for ACC and private insurance funding pathways.