It is normal to experience some pain as part of recovery in the initial weeks to months after surgery. However, persistent, severe pain beyond the expected healing period may indicate issues such as implant loosening, infection, or instability. Patients may notice different types of pain, including a deep ache, sharp pain during movement, or pain that worsens with weight-bearing activities. Each may signal specific issues and should be assessed by a healthcare professional if it persists.

Instability in a knee replacement can feel like the knee is “giving out” or not fully supporting weight, particularly during activities like walking or climbing stairs. This may result from ligament imbalance, loosening of the implants, or poor alignment of the knee joint. An unstable knee replacement should be evaluated to prevent falls and further joint damage.

A successful knee replacement generally restores a range of motion suitable for daily activities. Difficulty in bending or straightening the knee can indicate complications such as scar tissue formation (arthrofibrosis), malalignment of the implant, or loosening of components. Prolonged stiffness that doesn’t improve with physiotherapy or exercise may require additional treatment to improve movement and comfort.

Some swelling is common shortly after surgery, but it usually subsides as the knee heals. Swelling that persists or worsens over time could be due to inflammation, infection, or an underlying issue with the implant. Swelling accompanied by warmth, redness, or tenderness may point to infection, which requires prompt medical attention to prevent further complications.

Mild warmth around the knee is common in early recovery however, persistent warmth, especially alongside redness, may suggest infection or inflammation. Bruising is typical after surgery, but ongoing skin discolouration or darkening around the knee can indicate problems, particularly if accompanied by pain and swelling.

While some minor clicking may occur as the knee moves, frequent or worsening sounds, such as grinding, may indicate joint misalignment or wear on the implant. If the knee feels rough or gritty during movement, this could suggest issues with the implant surfaces or loosening, which may impact function and comfort.

Infection is a serious but rare complication that can occur around a knee replacement. Signs include fever, chills, increasing pain, swelling, redness, or discharge from the incision. Infections can be challenging to treat and may require antibiotics or even revision surgery if the infection spreads to the implant.

Knee joint issues can sometimes place strain on other parts of the leg, causing pain in areas like the hip, thigh, or ankle. This may signal joint alignment issues or implant loosening. Sometimes, pain originating in the knee can be felt elsewhere. Monitoring any new or worsening pain in surrounding joints is important to assess overall joint function.

A knee replacement aims to improve mobility and quality of life. If patients notice a decline in their ability to walk, climb stairs, or perform everyday activities due to knee discomfort, this could indicate that the implant is not functioning as intended. If mobility deteriorates after initial improvement, a medical assessment can help determine the underlying cause and appropriate next steps.

Patients might notice visible changes in the knee’s alignment or shape, such as a bow-legged or knock-kneed appearance, which could signal implant loosening or instability. Bulging or indentation around the knee may also suggest implant issues or tissue swelling and should be reviewed by an orthopaedic specialist.