Papers of the Week

A significant subgroup of patients suffer from moderate or severe pain after total hip arthroplasty (THA). Regional analgesia has the potential to reduce postoperative pain and thereby spare patients from opioids, but regional analgesia of the hip is complicated as the area is innervated by multiple nerves. However, the nociceptors of the hip joint are primarily innervated by the obturator and femoral nerves. The effect of an obturator nerve block (ONB) on pain following THA has never been investigated. A femoral nerve block is known to reduce pain after THA, but is unfortunately accompanied by an increased risk of fall. We have developed a novel nerve block – the iliopsoas plane block (IPB) – that has the potential to anaesthetize the hip articular sensory branches of the femoral nerve without causing motor blockade. In conclusion, an IPB has the potential to provide analgesia after THA without inducing muscle weakness, but this hypothesis has to be tested in a clinical trial. An ONB does, on the other hand, not appear to provide postoperative analgesia after THA through the posterior approach.