Regional analgesia techniques for total knee replacement.

PURPOSE OF REVIEW: Pain following total knee arthroplasty is a challenging task for healthcare providers. Concurrently, fast recovery and early ambulation are required to regain function and to prevent postoperative complications. Ideal postoperative analgesia provides sufficient pain relief with minimal opioid consumption and preservation of motor strength. Regional analgesia techniques are broadly used to answer these expectations. Femoral nerve blocks are performed frequently but have suggested disadvantages, such as motor weakness. The use of lumbar epidurals is questioned because of the risk of epidural hematoma. Relatively new techniques, such as local infiltration analgesia or adductor canal blocks, are increasingly discussed. The present review discusses new findings and weight between known benefits and risks of all of these techniques for total knee arthroplasty.

RECENT FINDINGS: Femoral nerve blocks are the gold standard for total knee arthroplasty. The standard use of additional sciatic nerve blocks remains controversial. Lumbar epidurals possess an unfavourable risk/benefit ratio because of increased rate of epidural hematoma in orthopaedic patients and should be reserved for lower limb amputation; peripheral regional techniques provide comparable pain control, greater satisfaction and less risk than epidural analgesia. Although motor weakness might be greater with femoral nerve blocks compared with no regional analgesia, new data point towards a similar risk of falls after total knee arthroplasty with or without peripheral nerve blocks. Local infiltration analgesia and adductor canal blockade are promising recent techniques to gain adequate pain control with a minimum of undesired side-effects.

SUMMARY: Femoral nerve blocks are still the gold standard for an effective analgesia approach in knee arthroplasty and should be supplemented (if needed) by oral opioids. An additional sciatic nerve blockade is still controversial and should be an individual decision. Large-scale studies are needed to reinforce the promising results of newer regional techniques, such as local infiltration analgesia and adductor canal block.