The AAOS (American Association of Orthopaedic Surgeons) have published guidelines for those non-surgery factors influencing the outcome of total knee arthroplasty (TKA) - also called total knee replacement (TKR). I have summarised these for you to make items easy to refer to and remember.
Dr (Prof) RAJU VAISHYA
MBBS, MS, MCh (Liverpool), FRCS (Lon)
Indraprastha Apollo Hospitals,
New Delhi, INDIA
email: [email protected]
Tourniquet - yes or no?
"As surgeons, we are always looking for ways to improve the outcome for our patients after surgery. It is not only the surgery itself that influences outcome, but other factors may positively or negatively affect things."
Injecting usually quite a large volume of dilute long acting anaesthetic agent inside and around the wound. This may also contain an agent to constrict small blood vessels and help to contain bleeding.
Femoral and popliteal sciatic nerve blocks can be given using long-acting agents, and contribute to pain relief both during and after surgery. These are injections around these nerves.
This refers to spinal and epidural anaesthesia. In a spinal, the anaesthetic agent is injected inside the spinal canal, and the needle withdrawn. The dose is calculated from the person's body weight and the extent of numbing of the lower body depends upon the positioning of the patient as it takes effect.
An epidural relies upon a catheter placed in the epidural space near the spinal canal, and the agent is titrated during the procedure and afterwards if necessary, as the catheter can be left in for some hours.
A tourniquet is an inflatable band that is placed at the top of the thigh before surgery. The leg is raised, and the blood drained out, and then the tourniquet is pumped above the level of the blood pressure. This prevents any bleeding during surgery. The tourniquet should be released towards the end of the procedure, and any bleeders should be cauterised before the wound is closed.
Tourniquet use does mean, however, that the limb is bloodless for the period of the surgery. Also the muscles directly under the pressurised band can be a bit traumatised.
This is a medication that prevents blood clots from breaking down too rapidly. It can help to prevent excessive blood loss.
Cryotherapy means 'cold' therapy. In this context there is usually a fluid-filled cuff that goes around the leg, through which chilled water is circulated.