THE POST-OPERATIVE PAINFUL KNEE: CLINICAL AND SOCIETAL CAUSATION

Persistent post-surgical pain (PPSP) remains a problem after knee replacement with some studies reporting up to 20% incidence. Pain is usually felt by those who do not operate to be a monolithic entity. All orthopaedic surgeons know that this is not the case. At its most basic level, pain can be divided into two categories, mechanical and non-mechanical.Mechanical pain is like the pain of a fresh fracture. If the patient does not move, the pain is less. This type of pain is relieved by opiates. Mechanical pain is seen following knee replacement, but is becoming less frequent. It is caused by a combination of malrotations and maltranslations, often minor, which on their own would not produce problems. The combination of them, however, may produce a knee in which there is overload of the extensor mechanism or of the medial stabilizing structures. If these minor mechanical problems can be identified, then corrective surgery will help.Non-mechanical pain is present on a constant basis. It is not significantly...