What is Patellar Instability or Dislocation?

Patellar instability occurs when the kneecap (patella) shifts out of its normal groove. A full dislocation happens when the patella completely moves out of place, usually to the outside of the knee.

What happens in a patellar dislocation?

It usually occurs during sports when the knee twists or receives a direct blow. The patella slips out, causing immediate pain, swelling, and difficulty walking.

Common causes

  • Congenital shallow trochlear groove
  • Generalised ligament laxity
  • Trauma or twisting injury in sport
  • Weakness in the quadriceps or glutes

Who is most affected?

  • Adolescents aged 12–18
  • Female athletes have a higher risk due to a wider Q-angle
  • Common in netball, football, basketball, and gymnastics

Symptoms

  • Sudden pain and swelling at the front of the knee
  • Visible deformity if fully dislocated
  • Instability or fear of the knee ‘giving way’

📞 If your child’s kneecap dislocates or feels unstable, book an urgent assessment at Spinal and Sports Care.

Diagnosis

Clinical examination after injury:

  • Observation of patella position
  • X-ray to confirm alignment and rule out fracture
  • MRI may be used to assess cartilage and ligament damage

Treatment options

Non-surgical:

  • Reduction of dislocation (by a medical professional)
  • Immobilisation briefly, followed by physiotherapy
  • Strengthening quads, glutes, and core

Surgical:

  • Indicated for recurrent dislocations
  • MPFL reconstruction or trochleoplasty in severe cases

Role of physiotherapy

  • Restore quadriceps and glute strength
  • Improve knee stability
  • Correct biomechanics to prevent recurrence
  • Gradual return-to-sport program

Recovery timeline

  • First dislocation: 6–12 weeks with physiotherapy
  • Recurrent dislocation: may require 3–6 months and possible surgery

Prevention

  • Strengthen glutes, quads, and core
  • Neuromuscular training for cutting and landing
  • Early management after the first dislocation to prevent recurrence

Taping and bracing

  • Patellar stabilising braces can reduce recurrence risk
  • Taping may improve patella tracking during sport

When to see a physiotherapist or chiropractor

📞 If your child’s knee feels unstable or dislocates, seek immediate care at Spinal and Sports Care.

Frequently Asked Questions

When the kneecap shifts out of its groove.

A complete shift of the kneecap out of place, usually to the outside of the knee.

Adolescents aged 12–18.

Netball, football, basketball, gymnastics.

Clinical exam, X-ray, and MRI if needed.

Immobilisation, physiotherapy, or surgery if recurrent.

6 weeks to 6 months, depending on severity.

Yes, recurrence risk is up to 40% in young athletes.

No, only recurrent or severe cases.

Immediately after dislocation or if instability persists.