Isolated knee arthritis, or unicompartmental arthritis, occurs when wear and tear affects only one of the three compartments in your knee. These compartments include the inner (medial), outer (lateral), and front (patellofemoral) sections. Unlike widespread arthritis, isolated knee arthritis leaves most of the knee healthy and functioning normally.

Symptoms of Isolated Arthritis

Isolated knee arthritis presents differently from generalised knee arthritis. Common symptoms include:

Localised pain on one side: Discomfort typically occurs on the inner or outer side of the knee, especially during weight-bearing activities.

Morning stiffness that improves: The knee may feel stiff for the first 20-30 minutes after waking, but this usually eases with movement.

Clicking or catching sensations: These may occur in one specific area of the knee during certain movements.

Swelling in one area: Swelling tends to appear on one side of the joint rather than throughout the knee.

Risk Factors of Isolated Arthritis

Risk factors for isolated knee arthritis include:

  • Age-related joint wear, which occurs naturally over time
  • Previous knee injuries, such as fractures or ligament damage
  • Knee joint misalignment, which places uneven stress on the joint
  • Family history of osteoarthritis, suggesting a genetic link
  • Excess body weight, which increases pressure on the knee

How Isolated Arthritis is Diagnosed 

An orthopaedic surgeon will assess your symptoms and perform a physical examination. Imaging tests such as X-rays or MRI scans help confirm whether arthritis is limited to a single knee compartment. An accurate diagnosis of isolated knee arthritis is crucial. It indicates you might be a suitable candidate for a partial knee replacement, which focuses solely on the damaged area while preserving the healthy parts of your knee.

Partial Knee Replacement As a Treatment for Isolated Knee Arthritis 

Partial knee replacement, also called unicompartmental knee replacement, replaces only the damaged part of the knee while preserving healthy bone, cartilage, and ligaments. Unlike total knee replacement, which addresses the entire joint, this procedure focuses only on the affected compartment, offering a less invasive option for suitable patients. This makes it an ideal solution specifically for isolated knee arthritis.

The surgery typically takes 1 to 2 hours. Customised implants are placed to restore smooth joint movement within the damaged area. Because the healthy structures of the knee are preserved, many patients report that their knee feels more natural after recovery.

Hospital stays vary, with some patients able to return home the same day, depending on individual recovery progress.

When to Consult an Orthopaedic Surgeon in Singapore

If you experience persistent knee pain, stiffness, or reduced mobility that limits your daily activities, consider consulting an orthopaedic specialist in Singapore. If isolated arthritis is confirmed, your specialist will assess whether you may benefit from partial knee replacement.

Conclusion

Isolated knee arthritis does not always require total knee replacement. Partial knee replacement offers a targeted option that preserves healthy joint tissue while addressing the affected area.

Schedule a consultation with our orthopaedic surgeon in Singapore to explore whether this treatment is suitable for your condition.