Patellar Instability (Adult)

What is patellar instability?

Patellar instability means that the kneecap doesn't stay reliably in its groove — it can partially or fully dislocate, usually to the outer side. Some people experience a single dramatic dislocation; others have repeated episodes that gradually erode their confidence in the knee.

The underlying causes vary. Some people are born with anatomy that makes the kneecap more prone to dislocation — a shallow groove, a higher-riding kneecap, or particular alignment patterns. Others develop instability after a traumatic dislocation that stretched or damaged the supporting structures.

The pattern of instability matters. A first-time dislocation is treated differently from recurrent instability, and the underlying anatomy guides what management is most likely to work.

What does it feel like?

Symptoms range from outright dislocations to a more subtle sense that the kneecap can't be trusted. Common features include:

• Episodes where the kneecap visibly slips out of place

• A feeling of giving way, particularly when pivoting or twisting

• Pain at the front of the knee, especially during or after episodes

• Apprehension — a fear that the knee will give way again

• Swelling after instability episodes

Many people develop habits to avoid the knee giving way, sometimes to the point that they're avoiding activities they used to enjoy.

How is it diagnosed?

Examination is central to diagnosis. Specific tests assess kneecap stability, while a careful history establishes the pattern and frequency of episodes.

Imaging usually plays an important role. X-rays look at alignment, kneecap position and any associated bony injuries. MRI assesses the soft tissues — particularly the medial patellofemoral ligament — and checks for cartilage injury, which can occur alongside dislocation events.

It's also important to look at the underlying anatomical factors that may have contributed, because these often need to be addressed as part of the management plan.

What are the treatment options?

First-time dislocations are often managed without surgery — a structured rehabilitation programme, sometimes with bracing, allows the supporting structures to settle and many people don't have further episodes.

Recurrent instability is a different matter. When the kneecap continues to dislocate despite rehabilitation, surgical stabilisation is often considered. The specific procedure depends on the underlying anatomy — sometimes ligament reconstruction is enough; sometimes other bony procedures are also needed. Nev will work through this with you at your consultation so the plan reflects your specific situation.

When should you get it checked?

Seek a specialist assessment if:

• You've had one or more dislocations of the kneecap

• The knee gives way unpredictably

• You're avoiding activities because you don't trust the knee

• Episodes are becoming more frequent

• You want a proper assessment of why this is happening and what your options are

Recurrent instability rarely settles on its own. The right plan, started early, prevents the cumulative damage that repeated episodes can cause.