Reduction - Patella dislocation

Indications

Patella dislocation

Contraindications (absolute in bold)

Life or limb-threatening conditions

Associated complex fractures

Alternatives

Reduction in theatre

Informed consent

Medical emergency

Consent is not required if the patient lacks capacity or is unable to consent

Brief verbal discussion is recommended if the situation allows

or

Verbal consent

Less complex non-emergency procedure with low risk of complications

Potential complications

Failure (of reduction, recurrence or immobilisation)

Fracture

Procedural hygiene

Standard precautions

PPE: non-sterile gloves

Area

Any bed space

Staff

Procedural clinician and assistant

Equipment

None

Positioning

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

Sequence

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

Post-procedure care

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)

Ongoing care:

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

Patient advice:

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)

Tips

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

Discussion

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.

Peer review

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.

References

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

© Agency for Clinical Innovation 2021

Feedback