Femoral versus Multiple Nerve Blocks for Analgesia after Total Knee Arthroplasty

Abstract

BackgroundThe PROSPECT (Procedure-Specific Postoperative Pain Management) Group recommended a single injection femoral nerve block in 2008 as a guideline for analgesia after total knee arthroplasty. Other authors have recommended the addition of sciatic and obturator nerve blocks. The lateral femoral cutaneous nerve is also involved in pain syndrome following total knee arthroplasty. We hypothesized that preoperative blocking of all four nerves would offer superior analgesia to femoral nerve block alone.MethodsThis is a prospective, randomized, controlled, and observer-blinded clinical study. A total of 107 patients were randomly assigned to one of three groups: a femoral nerve block group, a multiple nerve block group, and a control group. All patients were treated postoperatively using patient-controlled intravenous analgesia with morphine. Pain intensity at rest, during flexion and extension, and morphine consumption were compared between groups over three days.ResultsA total of 90 patients completed the study protocol. Patients who received multiple nerve blocks experienced superior analgesia and had reduced morphine consumption during the postoperative period compared to the other two groups. Pain intensity during flexion was significantly lower in the “blocks” groups versus the control group. Morphine consumption was significantly higher in the control group.ConclusionsPain relief after total knee arthroplasty immediately after surgery and on the first postoperative day was significantly superior in patients who received multiple blocks preoperatively, with morphine consumption significantly lower during this period. A preoperative femoral nerve block alone produced partial and insufficient analgesia immediately after surgery and on the first postoperative day. (Clinical trial registration number (NIH): NCT01303120)

Perineural versus Intravenous Dexamethasone for Prolongation of Multiple Nerve Blocks for Pain Relief after Total Knee Arthroplasty

“…Systemic DXM decreases pain during motion, reduces pain and emesis after TKA [56,57]. Consequently, the administration of 8 mg DXM IV immediately before the performance of MNB can be recommended for several reasons: as one of the agents of a multimodal pain control method, for prolongation of MNB, which is the best method for preemptive regional analgesia in comparison with FNB alone [4], as an antiemetic drug [57], etc.…”

“…A significant limitation of this excellent method of anesthesia and analgesia "is its relatively short effect" [4] usually lasting less than 24 hours, even when a long-acting local anesthetic bupivacaine with adjuvant as adrenaline is applied [4]. The use of additional adjuvants were approbated in clinical practice with the aim of prolonging the duration of the single shot PNB, for example, clonidine [50], opioids [51], midazolam [52], ketamine [53] with little effect.…”

“…We used a preoperative single-shot MNB as part of the surgical anesthesia and for management of postoperative pain following TKA [4]. A significant limitation of this excellent method of anesthesia and analgesia "is its relatively short effect" [4] usually lasting less than 24 hours, even when a long-acting local anesthetic bupivacaine with adjuvant as adrenaline is applied [4].…”

“…The success of the sensory and motor blockade was examined 30 min after completion of the block as described in our previous trial [4]. The sensory function of each blocked nerve was evaluated using pinprick as described by Marhofer et al [39].…”

“…of femoral, popliteal sciatic, both branches of obturator nerve and lateral femoral cutaneous nerve, produces excellent perioperative analgesia and opioid spare effect during the day of surgery and the first post-op day [4]. A significant limitation of this method of analgesia following TKA is its relatively short effect, even after use of a long acting local anesthetic such as bupivacaine with adrenaline (LA) [4]. The use of a perineural catheter for continuous MNB use is unpractical, because three catheters have to be inserted for the blockade of femoral, sciatic and obturator nerves.…”