Reduction - Patella dislocation
Contraindications (absolute in bold)
Life or limb-threatening conditions
Associated complex fractures
Reduction in theatre
Consent is not required if the patient lacks capacity or is unable to consent
Brief verbal discussion is recommended if the situation allows
Less complex non-emergency procedure with low risk of complications
Failure (of reduction, recurrence or immobilisation)
PPE: non-sterile gloves
Any bed space
Procedural clinician and assistant
Supine on a bed
Medication (if existing pain, anxiety or after a failed attempt)
Intranasal fentanyl 1.5mcg/kg
Inhaled nitrous oxide
Morphine IV 5mg or 0.1mg/kg repeated as required
Examination for other injuries and fractures
Neurovascular assessment of foot (pulses, power and sensation)
Consider bedside pre-reduction X-rays (only if suspected associated fracture)
Place one hand around the affected limb’s ankle
Place the other hand resting on the lateral surface of the displaced patella
Extend the knee applying medial upwards force to the lateral patella
Relocation usually occurs as the knee is fully extended
Check X-ray, circulation and limb function:
Assess stability with gentle passive movement of patella
Reassess limb neurovascular status
Obtain post-reduction X-ray (patient should not leave the department until confirmed satisfactory)
Immobilise the affected knee in a Zimmer splint (2-4 weeks) and consider crutches
Discuss with orthopaedics on call (arrange GP or orthopaedic follow-up at two weeks)
Document procedure, neurovascular assessments, X-ray findings and follow-up plan
Advise to avoid bending, twisting and activities which cause pain
Advise there is a high chance of recurrence, best avoided by strengthening the knee muscles (physiotherapy)
Search for other fractures and serious injuries when treating a dislocated joint
Always perform a neurovascular exam before and after a relocation attempt
Reassurance, verbal distraction, effective pain relief and sedation all aid successful joint relocation
Early orthopaedics involvement is indicated for non-lateral dislocation, fractures or two failed reductions
Patellar dislocations are common sporting injuries, usually occurring after twisting an extended knee or a direct blow. This results in a lateral dislocation with the knee held flexed. Often, the patella may reduce spontaneously with leg straightening alone. Pre-reduction X-rays are not required unless an associated injury is suspected.
Distracting the patient can help be overcome hamstring tension and aid reduction. Pain relief will aid muscle relaxation but is often not required for reduction unless the patient is anxious or in already in pain. After a failed reduction attempt pain relief should be provided.
Non-lateral dislocations can occur and require orthopaedic consult, as they are often irreducible.
This guideline has been reviewed and approved by the following expert groups:
Emergency Care Institute
Please direct feedback for this procedure to ACI-ECIs@health.nsw.gov.au.
Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.
Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.
In: UpToDate. Waltham (MA): UpToDate. (2019): Recognition and initial management of patellar dislocations
Skinner H. Current diagnosis & treatment in orthopaedics. 5th ed. New York: McGraw-Hill Medical; 2013.
Ramponi D. Patellar dislocations and reduction procedure. Adv Emerg Nurs J. 2016;38(2):89-92. doi:10.1097/TME.0000000000000104