Most patients getting knee replacement surgery undergo spinal anesthesia with sedation, so they are not awake during the surgery. This type of anesthesia has many benefits, not the least of which is the continuation of pain relief for several hours after surgery. Additionally, spinal anesthesia has been demonstrated in studies to have other benefits, such as decreased surgical blood loss and a decreased risk of developing lower extremity blood clots when compared with general anesthesia. The muscle relaxation provided by spinal anesthesia also makes performing the surgery easier and therefore less traumatic for the patient.
After surgery, patients are treated with other pain medicine, mostly taken by mouth. While it may seem surprising, often the postoperative pain from knee replacement can be managed simply with oral pain medicine. This spares patients from the side effects of stronger intravenous medicines. On occasion, injections of pain medicine may be needed, until the day after surgery. After this, most pain medicine is provided in pill form as needed. Patients are often discharged with a prescription of the pills that worked for them during their hospital stay.
Patients can also help relieve their pain with means other than pain medicine. For example, applying ice and elevating the knee after therapy can go a long way toward controlling the swelling that often causes discomfort after such activity. On the other hand, when patients have discomfort from stiffness, usually doing some exercises will help relieve this pain more than any medicine will.