Comparing PENG and Femoral Nerve Blocks in Patients With Hip Fracture

Hip fractures are common orthopaedic problem especially in elderly population which is associated with significant morbidity and mortality. Early surgical reduction and fixation is the preferred treatment in most patients. Significant pain, if inadequately controlled, can impair early rehabilitation and functional recovery and can reduce patient satisfaction after surgery . Combinations of systemic analgesics, intra-articular injection, and neuraxial and peripheral nerve blocks should be considered as the integral components of the perioperative pain management plan. Among these, intra-articular local anaesthetic injections have been shown to play a potential role in providing analgesia after hip arthroplasty. The risks of this procedure include hematoma, nerve damage, local anaesthetics toxicity, intravenous injection of local anesthetics and septic osteoarthritis, but their occurrence is very rare. Several peripheral nerve blocks, including fascia iliaca block, femoral block (FB), and some interfascial plane blocks such as quadratus lumborum block (QLB), have also been suggested to decrease postoperative pain and opioid use. Lumbar plexus block/psoas compartment block is a technically difficult deep block that requires greater skill and hence can be time consuming. The lumbar paravertebral region is highly vascular and non-compressible. Hence, patients on anti-coagulation are at high risk for bleeding complications. There is also high risk of unintentional neuraxial block or inadvertent intravascular injection with local anaesthetic systemic toxicity. Some nerve branches responsible for hip joint innervation may not be blocked by QLB, which should be taken into consideration while using these blocks for hip fracture. High-volume suprainguinal fascia iliaca block and traditional fascia iliaca block have also been reported to be associated with a significant incidence of muscle weakness and to predispose the patient to fall. The anterior hip capsule is innervated by the obturator nerve (ON), accessory obturator nerve (AON), and femoral nerve (FN) as reported by previous anatomic studies. The anterior capsule is the most richly innervated section of the joint, suggesting these nerves should be the main targets for hip analgesia. Femoral block (FB) does not block the AON or the articular branches of the ON. Also, femoral nerve block accompanied by decreasing the strength of quadriceps muscles. Pericapsular nerve group (PENG) block was described in 2018 and reported that it was successfully used for postoperative pain management in hip surgery. The PENG block is a technique that involves deposition of local anaesthetic in the musculofascial plane between the psoas muscle and the superior pubic ramus for the blockade of the articular branches of the FN, ON and AON that provide sensory innervation to the anterior hip capsule.