Instability after total knee arthroplasty: Wobble and buckle

Instability after total knee arthroplasty (TKA) is a common reason for component failure and revision surgery. These patients require a thorough workup at presentation in order to accurately diagnose instability as being the cause for the patient's symptoms and to identify the reason for the knee instability. Instability after TKA is classified as global versus isolated instability. The isolated instability can be further categorized as extension instability, flexion instability, or recurvatum. The goal of revision surgery for instability is largely to recreate equal flexion and extension gaps. Good results can be obtained after revision surgery for instability.