Regional Anesthesia For Postoperative Pain Control

Updated: Dec 11, 2017
  • Author: Raymond Graber, MD; Chief Editor: Meda Raghavendra (Raghu), MD  more...
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In many centers, regional anesthesia techniques are used extensively to allow the performance of orthopedic procedures.

The intraoperative use of regional anesthesia has many advantages, including the following:

  • Reduces blood loss: In total hip arthroplasty (THA), studies have demonstrated that both spinal and epidural anesthesia tend to have approximately a 30% reduction in intraoperative blood loss compared with general anesthesia, owing to lower arterial and venous pressures. [1]

  • Reduces rates of deep venous thrombosis (DVT): Epidural and spinal anesthesia both reduce DVT risk by improving blood flow through the legs secondary to sympathectomy-induced vasodilatation; both anesthesia methods may also reduce perioperative hypercoagulability that occurs as a result of the surgical stress response. [1] A caveat is that many of the studies that showed decreased risk of DVT were from an era when routine thromboprophylaxis was not used.

  • Avoids common adverse effects of general anesthesia: Such adverse effects include nausea, sore throat, alteration of mental status, and cognitive dysfunction. [2]

  • Allows patient involvement: Some patients enjoy the ability to watch knee arthroscopic procedures on the video monitor.

  • Improves pain control: Regional techniques can block or reduce pain anywhere from several hours to several days, depending on the technique used. Preemptive pain management may reduce subsequent pain in the days to weeks following surgery. Greater pain control has the potential to allow for earlier hospital discharge and may improve the patient's ability to tolerate physical therapy.

Various regional analgesia techniques exist that can be used to promote postoperative pain relief. These methods can be categorized into neuraxial local analgesics and narcotics, peripheral nerve blocks, and wound infiltration.


Neuraxial Analgesia

Intrathecal analgesia

Intrathecal (IT) narcotics can offer effective postoperative analgesia. These agents bind with opioid receptor sites in the dorsal horn of the spinal cord, resulting in modulation of pain signals at the spinal cord level. IT narcotics can be administered as an adjunct to general anesthesia (eg, for scoliosis surgery), or they can be mixed with local anesthetics and administered during spinal anesthesia (eg, for total hip arthroplasty). For IT morphine, the onset of analgesia is 30-60 minutes, and the duration of analgesia is 18-24 hours, depending on the dose that is used.

Adverse effects of IT narcotics include nausea, pruritus, urinary retention, and respiratory depression. Respiratory depression from IT morphine peaks at approximately 7-9 hours after surgery and is dose dependent. The incidence of respiratory depression in 1 retrospective study was 0.36%, [3] but the incidence is probably lower now because smaller doses are currently used. The postinjection incidence of nausea and vomiting for IT morphine is approximately 20% and peaks at approximately 4 hours. Pruritus occurs in approximately 40% of patients, but severe cases (requiring treatment) occur in about 9%. [4] The incidence of urinary retention is unclear because many patients receive prophylactic catheterization, but it is estimated to occur in 10-40% of patients. [4]

The advantages of IT analgesia, especially if spinal anesthesia is already planned, include its simplicity, lack of need for catheter care or pumps, low cost, and easy supplementation with low-dose patient-controlled analgesia (PCA) narcotics as needed. The main disadvantages of this technique are limited duration of action (in comparison to catheter techniques) and the adverse effects discussed above. More frequent respiratory monitoring is recommended because of the risk of late-onset respiratory depression. [5]

Contraindications to use of IT anesthesia include heparinization or other coagulopathy, local or systemic infection, and morphine allergy.

Typical dosing regimens recommended in the literature are as follows:

  • Total hip arthroplasty – Morphine 100-200 mcg

  • Total knee arthroplasty – Morphine 200-300 mcg

  • Spine fusion, scoliosis surgery – Morphine 300 mcg or 3-5 mcg/kg

However, when used in knee and hip arthroplasty, the author limits the dose to 150 mcg. This is because now typically multimodal analgesics (celecoxib, acetaminophen, gabapentin) and peripheral nerve blocks are used in conjunction with IT morphine. Using a lower dose results in lower incidence of nausea, itching, and respiratory depression.

Epidural analgesia

Epidural analgesia is accomplished by means of epidural narcotics, local anesthetics, or their combination. Narcotics can be administered by bolus or infusion. Adverse effects are the same as those of IT narcotics (see Intrathecal analgesia, above). Epidural local anesthetics, typically diluted solutions of bupivacaine or ropivacaine, are administered by infusion. Adverse effects of epidural local anesthetics include urinary retention, motor block, and a sympathectomy-induced decrease in blood pressure. Epidural local anesthetics and narcotics are frequently combined in lower dosages to decrease the risk of each drug's associated adverse effects.

The duration of epidural infusion depends on several factors. Epidural catheters must be removed before the advent of significant anticoagulation from heparin, low-molecular-weight heparins (LMWHs), or warfarin (Coumadin; Bristol-Myers Squibb Co, Princeton, NJ). The authors generally remove epidural catheters by 72 hours to reduce the risk bacterial colonization at the catheter site.

A wide variety of dosing regimens for regional anesthesia are in use. Narcotic and local anesthetic drugs can be combined in the same infusion and run at a lower rate. Intravenous (IV) PCA narcotics can be administered as an adjunct to local anesthetic infusions.

Typical epidural infusions include the following:

  • Morphine (0.01%) – 5-10 mL/h

  • Fentanyl (0.001%) – 5-10 mL/h

  • Hydromorphone (0.005%) – 5-10 mL/h

  • Bupivacaine (0.05-0.1%) – 5-10 mL/h

  • Ropivacaine (0.1%) – 5-10 mL/h

An extended-release form of morphine is also available for epidural use (DepoDur; morphine sulfate extended-release liposome injection; Endo Pharmaceuticals Inc, Chadds Ford, Pa). DepoDur is said to provide 48 hours of analgesia, but this drug also has the typical adverse effect profile of epidural narcotics. DepoDur use has been reported in patients undergoing hip replacement [6] and knee replacement. [7]

Treatment of epidural or IT narcotic adverse effects is as follows:

  • Urinary retention – Urinary catheterization

  • Pruritus – Diphenhydramine (Benadryl; McNeil-PPC, Inc, Fort Washington, Pa) 25-50 mg IV or intramuscular (IM) route, or naloxone 0.1-0.2 mg IV or subcutaneous (SC) route

  • Nausea/vomiting – Metoclopramide (Reglan; Baxter Healthcare Corp, Deerfield, Ill) 10 mg IV; ondansetron (Zofran; GlaxoSmithKline, Research Triangle Park, NC) 4 mg IV; droperidol 0.625-1.25 mg IV; or naloxone 0.1-0.2 mg IV/SC

  • Respiratory depression – Naloxone 0.2-0.4 mg IV

Neuraxial blocks and anticoagulation

The American Society of Regional Anesthesia and Pain Medicine (ASRA) has made recommendations regarding the safe conduct of neuraxial blocks when patients are on anticoagulants before or after surgery. Three editions have been published, and work is underway on a fourth edition. [8] When any anticoagulant is administered perioperatively in a patient with a neuraxial catheter in place, close neurologic monitoring of the lower extremities is mandated. Some common scenarios follow.


  • 5000 U BID SC dosing: No contraindication

  • >10,000 U SC/day: Unclear risk; possible prothrombin time (PT) elevation in some patients (may be helpful to check activated clotting time [ACT])

  • If greater than 4 days of heparin, check platelet count to rule out heparin-induced thrombocytopenia

  • Intraoperative IV heparinization: Delay heparin for 1 hour after needle insertion.

  • Removing catheters: Wait 2-4 hours after last dose or infusion stopped and check ACT or partial thromboplastin time (PTT); then, pull catheter; restart heparin 1 hour after catheter removal


  • Preoperative prophylactic dose: Wait 10-12 hours after last dose (enoxaparin 30 mg q12h or enoxaparin 40 mg SC qd)

  • Preoperative treatment dose: Wait 24 hours after last dose (Enoxaparin 1 mg/kg q12h or enoxaparin 1.5 mg/kg qd or dalteparin 200 u/kg qd or tinzaparin 175 u/kg qd)

  • Postoperative prophylactic dose BID dosing: First dose greater than 24 hours postoperatively and more than 2 hours after removal of epidural catheter

  • Postoperative prophylactic dose single daily dosing: First dose 6-8 hours postoperatively; second dose 24 hours later; catheter removal more than 10-12 hours after a dose, but more than 2 hours prior to next dose; thus, about a 10-hour window to remove catheter


  • Preoperatively: Stop warfarin 5 days prior to the procedure and check the international normalized ratio (INR); INR less than or equal to 1.4 is acceptable

  • Postoperative warfarin: Remove catheters when INR is less than 1.5; if INR is 1.5-3, remove with caution and do not remove if concurrent antiplatelet or other antihemostatic agents are in use; Perform frequent neurologic checks; If INR is greater than 3, hold warfarin

Antiplatelet drugs

  • NSAIDs: No contraindication to neuraxial block

  • Clopidogrel (Plavix): Wait 7 days after last dose (5 days may be acceptable if normalization of platelet function can be shown)

The 3rd Edition ASRA Guidelines did not include recomendations for many of the newer anticoagulant drugs that have since come to market. While work continues on the full 4th Edition, ASRA has posted draft recommended time intervals before and after neuraxial block or catheter removal for some of these drugs here.

Preliminary ASRA Recommendations for New Anticoagulants (Open Table in a new window)


Time Before Puncture, Catheter Manipulation or Removal

Time After Puncture, Catheter Manipulation or Removal

Dabigatran         5 days 6 hours
Apixiban  5 days 6 hours
Rivaroxaban  3 days  6 hours
Prasugrel 7-10 days 6 hours
Ticagrelor 5-7 days 6 hours

Fondaparinux (Arixtra) is another newer anticoagulant being used for thromboprophylaxis. It is a factor Xa inhibitor and is given as a subcutaneous injection as an alternative to heparin or LMWH. Its half-life is 17-21 hours but is prolonged in patients with renal dysfunction. Because of a lack of adequate studies, ASRA has not been able to issue any evidence-based guidelines on safe conduct of neuraxial anesthesia in patients receiving this drug. For the time being, the author would recommend the last dose be administered greater than 4 days prior to neuraxial block in patients with normal kidneys or mild dysfunction. In patients with moderate or worse renal dysfunction, this period should be even longer. This rationale is based on waiting about 5 half-lives after drug admninistration and not on any outcome studies. [9]  This time interval has also been recommended in another ASRA-sponsored guideline regarding the performance of interventional spine and pain procedures in patients on antiplatelet and anticoagulant medications. [10]


Peripheral Nerve Blocks

Peripheral nerve blocks can provide significant pain relief. Nerve blocks can either be combined with general anesthesia or used as the sole anesthetic. [11] Long-acting local anesthetics, such as bupivacaine or ropivacaine, provide nerve-block duration of approximately 12-18 hours. Certain additives may prolong this duration; for example, the addition of dexamethasone or methylprednisolone may provide an additional 6-10 hours of analgesia. [12, 13] However, longer duration can best be reliably achieved by the perineural placement of catheters, which are then infused continuously, or bolused as needed.

Serious adverse effects of peripheral nerve blocks are rare. Adverse effects can be categorized as due to either local anesthetic toxicity, complications of needle placement, or spillover of local anesthetic to the surrounding neural structures. Local anesthetic toxicity can occur because of unplanned intravascular injection or slow absorption from the injection site. This can manifest as reactions ranging from tinnitus and dizziness to convulsions and cardiac arrest. Complications of needle placement can include hematomas, dysesthesias (0.2%), [14] and other problems related to the specific nerve block. Spillover adverse effects are manifested mainly in interscalene and supraclavicular blocks.

Peripheral nerve blocks have the advantages of no sympathectomy-induced decrease in blood pressure and no narcotic-related adverse effects such as urinary retention, nausea, or itching. However, some degree of motor block is observed with the sensory block. This result may limit the usefulness of some peripheral blocks in certain situations. For example, prolonged femoral blocks are a good choice for pain control in anterior cruciate ligament (ACL) reconstructions, but they are not a good choice in knee arthroscopy because the quadriceps motor block would prevent safe ambulation.

Successful use of nerve blocks depends not only on clinical knowledge of the site of incision innervation but also on knowledge of the innervation for the underlying bone and muscular tissue.

Brachial plexus blocks

The brachial plexus can be anesthetized at sites above the clavicle (interscalene and supraclavicular approaches) or below the clavicle (infraclavicular and axillary approaches). The interscalene approach is used for shoulder and upper arm surgery because the roots of both the brachial and cervical plexuses are anesthetized. This is generally not a good approach for lower arm or hand surgery because the C8 and T1 nerve roots are frequently inadequately anesthetized. The supraclavicular approach can result in good block of the arm and hand. The infraclavicular or axillary approaches are used for surgery of the elbow, lower arm, and hand.

Interscalene and supraclavicular blocks, although safely performed in most patients, have more adverse effects and risks associated with them. Phrenic nerve dysfunction occurs in 100% of interscalene blocks [15] and 25-50% of supraclavicular blocks. [16] Thus, these blocks may not be well tolerated in patients with preexisting respiratory compromise. Research suggests that pulmonary function can be preserved by using lower-volume, lower-concentration, and lower-level (C7) ultrasound-guided approaches. [17, 18] Case reports describe epidural [19] or IT injections [20] with interscalene blocks. Pneumothorax has been reported to occur in up to 5% of supraclavicular blocks, but the incidence is probably now much less than 1% with the advent of ultrasound-guided techniques. Horner syndrome and hoarseness commonly occur from spread of anesthetic to the sympathetic chain and recurrent laryngeal nerve, respectively.

For hand surgeries, more distal blocks can also be performed to provide analgesia. Block of the radial, median, and ulnar nerves at the wrist or block of the digital nerves of the fingers (see the images below) can be performed.

Palmar digital nerves. Palmar digital nerves.
Dorsal digital nerves. Dorsal digital nerves.

Leg blocks

The knee joint is innervated by the femoral (anteriorly), sciatic (posteriorly), obturator (medially), and lateral femoral cutaneous nerves (laterally). Femoral nerve blocks are frequently used for analgesia after knee surgery; however, the degree of analgesia depends on the amount of surgical trespass into other nerve distributions. Thus, patients undergoing arthroscopic ACL and patellar surgery obtain excellent pain relief after femoral block, whereas patients undergoing knee replacement surgery frequently have severe posterior pain of sciatic origin. Unless the knee is properly braced, weightbearing and ambulation may need to be restricted until quadriceps function recovers in patients with femoral nerve blocks.

Sciatic nerve or popliteal fossa blocks are performed to provide analgesia after foot surgery. The popliteal fossa block is a block of the sciatic nerve in the popliteal fossa in the vicinity of the sciatic nerve's division into the tibial and common peroneal nerves. The advantage of a popliteal fossa block over standard sciatic blocks is that hamstring function is maintained. A saphenous block can be added if the site of surgery includes the medial malleolus.

For some foot or toe surgeries, more distal nerve blocks can also be performed to provide analgesia. Blocks of the deep peroneal, superficial peroneal, tibial, sural, and saphenous nerves can be performed at the ankle level, or block of the digital nerves of the toes can be used.


Wound Infiltration

The infiltration of wounds with local anesthetics not only provides analgesia but also appears to reduce the local inflammatory response to trauma or surgery. Thus, local infiltration may help reduce the upregulation of peripheral nociceptors that manifests as hypersensitivity to a stimulus. Local anesthetics have been administered incisionally, intraarticularly, and as higher volume infiltration of the wound.


Local anesthetic can be administered in skin incision sites or on bone wounds (iliac crest graft sites). Bupivacaine or ropivacaine provides approximately 6 hours of analgesia. Incisional catheters and local anesthetic infusions have been reported for use in general, thoracic, and cardiac surgeries, but appear to be less frequently reported in orthopedic surgery. In 2011, the FDA approved bupivacaine liposome injectable suspension (Exparel) for use in surgical pain. It is in effect a slow-release form of bupivacaine, which can provide analgesia for up to 72 hours. One of the early studies of its use was in bunionectomy patients, in whom improved analgesia and decreased narcotic need was shown. [21] Data on the safety and efficacy of its use in traditional nerve blocks and for wound infiltration in other types of orthopedic surgery are not yet available.

See the image below.

Skin infiltration with local anesthetic. Skin infiltration with local anesthetic.

Intraarticular local anesthetics

Single intraarticular injections of local anesthetics have been used for a long time in knee and shoulder arthroscopy, with presumed benign effect. A more recent innovation is to place an intraarticular catheter and to send the patient home with a disposable local anesthetic infusion pump. There have now been multiple case reports of glenohumeral cartilage damage (chondrolysis) after shoulder intraarticular infusions. [22, 23] More recently, intraarticular infusions have also been associated with chondrolysis of the elbow and knee. [24, 25] Local anesthetics have now been shown to have cartilage toxicity issues in both animal in vivo and human cartilage in vitro studies. [26, 27]

The potential toxicity appears to depend on the concentration of local anesthetic, duration of exposure, and possibly other factors such as pH and the presence of other additives. [28] Home-going intraarticular infusions can no longer be considered a safe practice. The risk of significant cartilage toxicity from single injections of low-dose local anesthetics is thought to be low.

Intraarticular narcotics

Peripherally located opioid receptors have been discovered in animals. Animal studies suggest that intraarticular inflammation induces the development of synovial opioid binding sites. In addition, intraarticular opioid administration appears to have an anti-inflammatory effect. Based on these observations, intraarticular narcotics are administered in knee and shoulder surgery.

The effect of intraarticular morphine in knee arthroscopy has been examined in multiple studies. A meta-analysis concluded that a mild analgesic effect of intraarticular morphine is observed, but a systemic effect cannot be excluded completely. [29] Whether a dose-response effect is observed and what the optimal dose is are still in question. Morphine doses of 1-5 mg have been used.

Regarding shoulder surgery, in a study of patients undergoing open rotator cuff repairs, patients receiving a combination of 1 mg of morphine with 20 mL of 0.25% bupivacaine had better postoperative pain relief than those patients receiving bupivacaine alone. [30]

Local infiltration analgesia

In 2008, Kerr and Kohan described their technique of systematic infiltration of a mixture of ropivacaine, ketorolac, and epinephrine into the tissues around the surgical field in total knee and hip arthroplasty, and named it "local infiltration analgesia" (LIA). [31] They described low pain scores, low narcotic requirements, early immobilization, and earlier hospital discharge. This was a nonrandomized uncontrolled case series. Since that first report, multiple other studies have examined the effectiveness of this technique or variations thereof.

In 2011, Kehlet and Andersen published a review of this topic. [32] They thought that many studies had design problems by not being placebo-controlled or with comparable systemic analgesia provided in the investigated groups. They concluded that little evidence supports the use of the technique in hip replacement, provided multimodal, oral nonopioid analgesia is given. However, they did believe this technique has a place in knee replacement surgery.

It may be that this technique is best used to complement traditional regional anesthetic techniques. For example, in 2012, Mahadevan et al compared femoral and sciatic nerve blocks versus femoral and periarticular infiltration with levobupivacaine for total knee arthroplasty. [33] No significant difference was noted between the groups in pain scores, morphine consumption, or range of motion. Thus, by avoiding sciatic nerve block, more motor function of the leg is preserved in the early postoperative period.


Analgesic Options for Specific Surgeries

For any specific surgery type, several regional anesthetic pain management options may be present. The choices may include the above-mentioned wound infiltration, neuraxial or peripheral nerve block techniques, or a combination of techniques. Analgesic techniques are selected based on the surgical trauma, goals for physical therapy, expected length of patients' hospital stay, and avoidance of adverse effects.

Spine surgery

IT morphine has been used as an adjunct in complex spine surgery such as scoliosis surgery. [34] Iliac crest harvest site infiltration with morphine and local anesthetic is an option.

Shoulder/arm/hand surgery

Shoulder surgery can be performed under interscalene nerve block or a combination of general and interscalene block. Complete pain relief can be achieved (for the duration of the block) unless the incision extends close to the axilla or there are posterior arthroscopy portals out of the block territory.

Interscalene catheters can be placed and infused for prolonged analgesia. Mariano et al compared continuous versus single-injection interscalene blocks. In a randomized, triple-masked, placebo-controlled study, interscalene catheters were placed preoperatively in 30 patients using an ultrasound-guided, in-plane posterior approach. All subjects received an initial bolus of ropivacaine. Postoperatively, the patients were discharged with oral opioid analgesics and a portable infusion device containing either ropivacaine 0.2% or normal saline; the devices were programmed to deliver a perineural infusion over 2 days. Patients who received the ropivacaine infusion experienced greater pain relief, used less oral opioids, suffered fewer sleep disturbances, and rated their satisfaction with analgesia higher. [35]

Other pain management options include subacromial or intra-articular morphine and local anesthetic.

Interscalene, axillary, and infraclavicular catheters can be placed for prolonged pain relief or arm surgery. Besides pain relief, the arm sympathectomy may be of value in certain operations involving vascular repairs.

Hip surgery

IT morphine is very effective for pain control after hip surgery in the first 12-24 hours. [36] Extended-release epidural morphine can provide analgesia for 48 hours. [6]

Epidural local anesthetic and narcotic can be infused. The duration of the infusion is limited by perioperative anticoagulation for DVT prophylaxis and by the need to terminate motor nerve block so that physical therapy can be performed.

Lumbar plexus blocks and catheters are used in some institutions to provide postoperative analgesia. Marino et al compared continuous lumbar plexus block with patient-controlled analgesia, continuous femoral block with patient-controlled analgesia, and patient-controlled analgesia alone in 225 patients who underwent unilateral total hip arthroplasty for osteoarthritis. [37] Compared with continuous femoral nerve block and patient-controlled analgesia alone, continuous lumbar plexus block significantly reduced pain scores during physiotherapy on postoperative day 1 and day 2 and was associated with fewer opioid-related adverse effects, greater distances walked, and enhanced patient satisfaction. Additionally, both regional anesthesia techniques provided significantly greater reductions in total hydromorphone consumption and delirium than patient-controlled analgesia alone.

Knee arthroplasty

IT morphine can be used for pain control after knee arthroplasty in the first 12-24 hours. Extended-release epidural morphine can provide analgesia for 48 hours. [7]

As with hip surgery, epidural local anesthetic and narcotic can be infused, but the infusion duration is limited by perioperative anticoagulation for DVT prophylaxis. Other issues include potential for sympathectomy and bilateral leg motor weakness, both of which have potential to interfere with the performance of physical therapy.

Femoral nerve blocks and perineural infusions offer very effective analgesia of the anterior knee after knee replacement surgery. Multiple studies have shown the effectiveness of this technique. [38]

With femoral nerve blocks, patients typically have improved range of motion, but quadriceps weakness can increase the risk of falling. Sharma et al determined the complication rate associated with preoperative femoral nerve block for total knee arthroplasty. [39] In 1018 total knee arthroplasties, 709 femoral nerve blocks were used by single-injection technique. Twelve patients treated with femoral nerve block sustained falls, 3 of whom required reoperation. The authors recommended that postoperative protocols be modified for patients who have femoral nerve block, because of decreased quadriceps function in the early postoperative period.

Preliminary reports describe that performing femoral block more distally (in the adductor canal) may have a motor-sparing effect and still provide good analgesia. [40, 41]  Because early ambulation and early physical therapy have become an increasing focus after joint replacement surgery, many centers have switched from traditional femoral blocks to using adductor canal blocks  for analgesia after knee arthroplasty. 

Approximately 80% of patients with femoral nerve blocks have posterior knee pain that is of sciatic origin. There are multiple strategies to deal with this, each with pros and cons, such as (1) sciatic nerve single injection or catheter, (2) surgeon-performed local anesthetic injections, (3) transcapsular injection.

Sciatic nerve single injection or catheter

A sciatic catheter provides the longest and most effective posterior pain relief. The downsides include an extra catheter and pump for the patient to deal with, potential for motor block and decreased ability to participate in physical therapy, and increased falls risk. In addition, a preoperative block reduces the ability to make an early diagnosis of any surgery-related peroneal nerve injury. Sciatic nerve block does not appear to allow earlier hospital discharge or change any functional outcomes. [42, 43] Sinha recently compared selective tibial nerve block to sciatic nerve block performed at the popliteal fossa. [44] The tibial nerve block group had similar (and excellent) analgesia, but without complete peroneal motor block.

Surgeon performed local anesthetic injections

Multiple variations in technique are described, including posterior capsular injections, [45] transcruciate injections into the space behind the joint capsule, [46] and intra-articular catheters. These techniques have the advantage of being easy to perform and, in general, have no associated motor block. The duration of analgesia is probably limited to the day of surgery.

Transcapsular injection

A transcapsular injection, which is a modification of the previously mentioned transcruciate injection technique, can also be used. It is performed by the surgeon after preparation of the distal femoral and proximal tibia at the time of either posterior cruciate retaining or substituting total knee replacement.

With the knee flexed to 90°, the landmarks in the area of the intracondylar notch are identified. Flexing the knee and avoidance of any external compression in the area of the popliteal fossa allows the neurovascular structures in the area to fall away from the site of injection. An 18-gauge Tuohy needle is inserted in the anterior-medial corner of the intracondylar notch and carefully directed cephalad in line with the posterior cortex of the distal femur. Insertion of the needle in this position, rather than directly through the substance of the posterior cruciate ligament, increases the distance between the injection site and the popliteal neurovascular structures and reduces the risk of intravascular injection.

A distinctive loss of resistance is typically noted as the needle penetrates the posterior capsule of the knee if the capsule has been undisturbed during the surgery. After the capsule is penetrated with the Tuohy needle, the site is aspirated to verify that the needle is not intravascular and the area injected with 20 mL of 0.25% Marcaine without epinephrine. If any resistance is encountered during the injection, the needle can be advanced slightly, reaspirated, and the injection completed.

This transcapsular injection appears to block the terminal articular fibers of the posterior joint, without any of the typical sensory and motor block seen when the sciatic nerve is anesthetized.

At our institution, we generally do the following:

  1. Use multimodal analgesics, which includes perioperative acetaminophen and ketorolac.

  2. Spinal anesthesia.

  3. Adductor canal block.

  4. Intraoperative transcapsular injections and wound infiltration by the surgeon.

  5. Postoperative parenteral or oral narcotics as needed.

  6. On rare occasions, a postoperative sciatic block is performed to deal with significant posterior pain.

Knee arthroscopic procedures

Femoral block can provide excellent analgesia for anterior cruciate ligament repairs with patella tendon grafts. [47] For more prolonged analgesia, femoral nerve catheters can be placed and infused at home via disposable pump. [48] If a quadriceps tendon graft is used, there may be significant posterior pain that is amenable to sciatic nerve block.

For patient pain control in arthroscopy/meniscectomy, intraarticular local anesthetic and morphine are used routinely. Long-acting femoral blocks are avoided so that patient ambulation is not impeded.


Foot and ankle pain can be controlled with a popliteal fossa block. The saphenous nerve may also need to be blocked if the surgical incision is on the medial aspect of the foot or ankle.


Other Aspects of Pain Management

Peripheral nerve blocks can provide excellent pain relief but have the problem of limited duration. An example of this scenario is a rotator cuff operation performed with a bupivacaine interscalene block. The sudden return of pain 12-18 hours after the bupivacaine interscalene block can be very distressing to the patient and result in the need for large doses of narcotics to control the patient's pain. Strategies to manage such a need include the following:

Perioperative narcotics

It is a good strategy for the patient to receive a dose of narcotic before the expected time of nerve-block resolution. The authors typically have patient narcotic IV PCA pumps already set up and in use before the removal of epidural catheters. OxyContin (oxycodone HCl controlled-release tablets; Purdue Pharma LP, Stamford, Conn) has been used as an effective analgesic for orthopedic procedures. For example, the first dose of OxyContin can be administered 10-12 hours after the placement of a bupivacaine interscalene nerve block for shoulder surgery. As-needed narcotics should always be available for pain control once the nerve block has terminated.

Multimodal analgesia

Many centers supplement regional anesthesia techniques with a regimen of oral or IV analgesic medications, with the following goals in mind:

  • Preemptive analgesia – The theory that certain medications may help reduce the up-regulation of nociceptors at peripheral or central locations when pain does occur [49]

  • Improved analgesia during the block – Some techniques reduce pain but do not completely eliminate it; multimodal analgesia helps cover this breakthrough pain and helps reduce narcotic requirements

  • Reduced intensity of pain when the block wears off, because the patient already has analgesics in his or her system

Typical regimens include scheduled administration of IV or oral acetaminophen, NSAIDs (IV ketorolac or oral celecoxib ), and neuropathic pain relievers such as gabapentin or pregabalin. A preincisional dose of dexamethasone may also be of benefit. [50]

Perioperative NSAIDs

As mentioned, NSAIDs can be used as a supplement to narcotics. Intravenous ketorolac (Toradol; Roche Laboratories Inc, Nutley, NJ) 15-30 mg IV every 6 hours is a very effective pain reliever of orthopedic pain, and without respiratory depressant effects. As an NSAID, it does have antiplatelet effects and has the potential to increase wound drainage, especially in patients who are receiving postoperative thromboembolic prophylaxis.

Another alternative is the oral cyclooxygenase-2 (COX-2)–inhibitor drug celecoxib (Celebrex; Pfizer Inc, New York, NY). Celecoxib can be administered preoperatively as a 200-400 mg load, then continued with a dose of 200 mg orally once a day. The advantage of this drug is that it does not cause significant platelet dysfunction, so it is less likely to contribute to excessive wound drainage. However, there is controversy regarding the use of celecoxib in patients with known cardiac disease or with risk factors for cardiac disease.

The potential adverse effects associated with the use of NSAIDs include platelet dysfunction, renal dysfunction, and gastric ulceration (especially in patients receiving oral anticoagulants). Of special concern in orthopedic surgery, there is potential for decreased bone growth and healing, which might have an impact on fusion success rates following spinal surgery or bone healing after fracture surgery. [51]