In local anaesthesia (also called partial anaesthesia) only the affected body part is anaesthetised. The patient remains awake during surgery, can listen to music or even follow the operation on a screen. Alternatively, a sleep-inducing drug is administered: the patient sleeps during the operation without being fully anaesthetised (sedation).
The most common type of local anaesthesia during the implantation of artificial joints is a regional anaesthesia in the area of the spinal cord. A distinction is made between spinal anaesthesia and epidural anaesthesia.
In spinal anaesthesia, an anaesthetic drug is injected into the fluid surrounding the spinal cord. This renders the patient completely pain-free and largely desensitised but also paralysed in the lower part of the body. This type of anaesthesia lasts about 2-5 hours.
In epidural anaesthesia, the drug is not injected directly into the spinal fluid but into the immediately adjacent space between the spinal cord membrane and the vertebral canal (known as epidural space). Often a small plastic catheter is placed into this space through which pain medication can be administered. This makes it possible to better control the duration of the anaesthesia, which may last between a few hours and several days.