Research Progress on Postoperative Analgesia After Total Hip Arthroplasty

Total hip arthroplasty (THA) is a highly effective treatment for end-stage osteoarthritis and hip fractures, significantly enhancing patients' quality of life. However, substantial postoperative pain remains a challenge, potentially impeding rehabilitation, prolonging hospitalization, and increasing the risk of chronic pain and subsequent revision surgeries. Multimodal analgesia (MA), which combines two or more analgesic methods with different mechanisms, is commonly employed in clinical practice to manage postoperative pain in THA. Among these methods, regional nerve blocks and local infiltration analgesia (LIA) have gained increasing attention due to their excellent analgesic effects and relatively few adverse reactions. This article reviews the two primary analgesic methods for postoperative THA: regional nerve blocks, including the emerging pericapsular nerve group block (PENG block), and LIA. Regional nerve blocks, such as femoral nerve block (FNB) and PENG block, have demonstrated efficacy in reducing postoperative pain and opioid consumption while preserving quadriceps muscle strength, thereby promoting rapid postoperative recovery. The PENG block, in particular, has shown promise as a preferred nerve block option for THA due to its ability to effectively block multiple nerves supplying the hip joint without affecting lower limb muscle strength. LIA, involving the infiltration of a high-volume local anesthetic solution around the joint capsule and surgical incision, has also proven to be a simple, cost-effective, and efficacious method for acute pain control after THA. Its analgesic effects are comparable to those of intrathecal morphine injection or peripheral nerve blocks, and it does not affect lower limb muscle strength. Combining LIA with nerve blocks such as PENG and FNB can further enhance multimodal analgesia. However, there is currently no unified formula for the drug composition of LIA, and research on liposomal bupivacaine, a sustained-release formulation of bupivacaine, has yielded varying results regarding its benefits. Overall, current evidence supports the use of regional nerve blocks, particularly the PENG block, and LIA as effective analgesic methods for postoperative THA, with the potential for further optimization through combination therapies and standardized protocols.