Abstract
Noise in the knee joint is a common symptom that often leads to outpatient clinic visits. However, there have been no previous review articles regarding noise around the knee despite its high prevalence. We will review the noise characteristics according to sound nature and onset as well as factors for differentiation between physiological and pathological noises. In addition, we will describe causes of the physiological and pathological noises and management of noise in the knee. An appropriate review of the characteristics of noise, its pathophysiology, and factors for differentiation between physiological and pathological noises can facilitate patient guidance. It is important to differentiate between physiological noise and pathologic noise. In most cases, noise after surgery is simply the perception of noise that had been present previously due to emotional concerns. Minor problems associated with surgery, such as postoperative noise, can decrease patient satisfaction, especially among patients with high expectations. Following surgical principles and providing accurate information about physiological noise can decrease the risk of both pathological noise and patient dissatisfaction. In total knee arthroplasty, every attempt should be made to avoid patellar crepitus and clunk by using modern prostheses with proper patellofemoral conformity and by avoiding surgical errors.