Background: Instability is one of the most common reasons for revision after a total knee replacement. It accounts for 17.4% of all single-stage revision procedures performed in the UK National Joint Registry. Through a careful patient evaluation, physical assessment and review of investigations one can identify the likely type of instability.
Aims: To critically examine the different types of instability, their presentation and evidence-based management options.
Method: A comprehensive literature search was conducted to identify articles relevant to the aetiology and management of instability in total knee replacements.
Results: Instability should be categorised as isolated or global and then, as flexion, mid-flexion, extension or recurvatum types. By identifying the aetiology of instability one can correctly restore balance and stability.
Conclusion: With careful judgement and meticulous surgical planning, instability can be addressed and revision surgery can provide patients with successful outcomes.
Keywords: Extension; Flexion; Instability; Knee Replacement; Mid-flexion; Recurvatum; Revision.
© 2021. The Author(s).