Numerous postoperative pain protocols exist for patients undergoing total knee arthroplasty (TKA). We compared the length of stay, early range of motion (ROM), and pain scores of a control group with a femoral nerve block to those of a group with femoral nerve block and local infiltration analgesia following TKA.
In a consecutive series of patients undergoing primary TKA at a Veterans Administration hospital, 40 patients (40 TKAs) who had local infiltration analgesia were compared to a historical group of 43 patients (43 TKAs) who had a long-acting femoral nerve block without local infiltration analgesia. Local infiltration analgesia consisted of intraoperative injection of 150 mL of 300 mg ropivacaine, 30 mg ketorolac, and 500 µg epinephrine using 50 mL into each of 3 areas: (1) posterior capsule, (2) medial and lateral capsule, and (3) anterior capsule and subcutaneous tissues. A 17-gauge intra-articular catheter was used to inject an additional 100 mg of ropivacaine on postoperative day 1. The control group had a single-shot femoral nerve block using 150 mg of ropivacaine with epinephrine. Mean length of stay for the local infiltration analgesia group compared to controls was 3.2±1.4 days vs 3.8±1.6 days, respectively (P=.03). No significant differences existed in average ROM (6 weeks), discharge hematocrit, transfusions, and temperature. Mean pain scores were lower in the local infiltration analgesia group on postoperative day 1 (P=.04), but not on postoperative day 2 or 3. Maximum visual analog scale scores (P<.01) were reduced in the local infiltration analgesia group.
Our early experience with local infiltration analgesia demonstrated a significantly reduced length of stay due to decreased postoperative pain.
Total knee arthroplasty (TKA) is normally associated with significant postoperative pain.1-3 Perioperative narcotics used to treat this pain are frequently associated with adverse effects such as nausea, emesis, ileus, urinary retention, confusion, and drug dependence.1,3,4 Multiple anesthetic and pain control protocols have been investigated and used to minimize perioperative pain.4-7
Multiple recent studies have documented the efficacy of local infiltration analgesia for TKA.8-12 However, only 1 published study demonstrated a reduced hospital stay in patients treated with local infiltration analgesia.13 The protocol used in the study was complex, requiring a 24-hour stay in the recovery room, around-the-clock administration of oral and parenteral medications, and a continuous infusion of ropivacaine.
We studied the clinical effect of a pain protocol in a consecutive series of patients undergoing primary unilateral TKA that used a preoperative short-acting femoral nerve block and local infiltration analgesia compared to a historical control group of patients who were treated with a long-acting femoral nerve block and postoperative patient-controlled analgesia with narcotics. We hypothesized that the substitution of this local infiltration analgesia protocol in place of patient-controlled analgesia narcotics would reduce hospital length of stay, lower postoperative pain scores, and result in fewer complications.
Materials and Methods
A consecutive series of primary unilateral TKAs were performed in patients who were treated with local infiltration analgesia from February 2010 to June 2010. A historical control group of similar patients who had undergone primary TKA just prior to the beginning of this study (November 2009 to February 2010) using postoperative patient-controlled analgesia narcotics were compared. Patients undergoing unicompartmental knee arthroplasty were excluded. All patients underwent surgery at a blinded Veterans Administration hospital. Institutional Review Board approval was obtained for this retrospective study.
The control group consisted of 43 patients (39 men and 4 women). Of the 42 local infiltration analgesia patients, 2 were excluded, leaving 40 patients (37 men and 3 women). The 2 patients who were excluded included 1 who had 2 esophagogastoduodenoscopies due to recurrent upper gastrointestinal tract bleeds (length of stay, 30 days) and another who had a myocardial infarction on postoperative day 2 (length of stay, 12 days). There was no statistical difference between groups in average age (control group, 65.2 years; local infiltration analgesia group, 65.9 years [P=.72]), or average preoperative hematocrit (control group, 42.2; local infiltration analgesia group, 42.2 [P=.93]). All patients were followed for a minimum of 1 month after discharge.
The patients in the control group received a preoperative single-injection femoral nerve block using 30 mL of 0.5% ropivacaine plus 1:200 epinephrine and 40 mg methylprednisolone acetate. This protocol resulted in a prolonged femoral nerve block with a motor blockade in some patients. Postoperatively, these patients had patient-controlled analgesia using intravenous morphine or hydromorphone.
Local Infiltration Analgesia Group
All but 1 patient in the study group received a single-injection femoral nerve block using 15 mL 0.25% ropivacaine with 1:200 epinephrine; instead, this patient received a spinal anesthetic. The volume of ropivacaine was smaller, and methylprednisolone acetate was omitted to lower the overall amount of ropivacaine given, to provide a shorter acting block, and to prevent a motor blockade. Patient-controlled analgesia narcotics were not used postoperatively in local infiltration analgesia patients unless required by pain that was not controlled by oral medications.
All but 1 patient in both groups received general endotracheal anesthesia in combination with the single-injection femoral block. One local infiltration analgesia patient had a spinal anesthetic (without intrathecal narcotics) supplemented by general anesthesia without a block. A Foley catheter and tourniquet were used for all patients in both groups. A median parapatellar or midvastus approach was used for exposure. Cemented posterior-stabilized total knee prostheses with patellar implants were used in all patients in both groups.
Local Infiltration Analgesia Technique
A mixture of 300 mg ropivacaine (0.2%) (150 mL), 30 mg ketorolac (1 mL), and 500 µg of epinephrine (1:1000) (0.5 mL) was prepared on the sterile field by the surgical technician and was injected in 3 equal 50 mL doses into each of 3 locations: (1) the posterior capsule, (2) the medial, lateral capsule and the edges of the capsular incision, and (3) the subcutaneous tissue along both edges of the incision. An 18-gauge spinal needle was used for infiltration.
After completion of all of the bone cuts for the TKA while the posterior capsule was easily visible, the initial injection of the posterior capsule was done using 50 mL of the ropivacaine mixture. The injection of the posterior capsule was done in a systematic fashion, equally dividing it into fifths. The needle was advanced through the posterior capsule by approximately 3 mm; typically, a palpable pop of the needle is felt when it penetrates the capsule. Aspiration is done to ensure that intravascular injection is not done, and 10 cc is injected. This procedure is repeated from the medial to the lateral aspect of the posterior capsule. The remainder of the capsular infiltration (medial, lateral, and incision line) is completed after final components are implanted and while the bone cement is polymerizing so that operative time is not wasted.
During cement polymerization, a 17-gauge epidural catheter with an external bacterial filter was placed intra-articularly adjacent to the medial femoral condyle with its tip close to the posterior capsule. The catheter was brought out of the joint through the vastus medialis muscle or adjacent to the drain through iliotibial band fascia. A single one-eighth-inch drain was used for all patients.
In the control group, patient-controlled analgesia narcotics were discontinued on postoperative day 2 in most cases. Thereafter, oral narcotics including hydrocodone and oxycodone were given on an as-needed basis around the clock. Oral oxycodone and hydrocodone were used immediately postoperatively in the local infiltration analgesia group. Both groups of patients were treated with mobile external compression (ActiveCare+S.F.T.; Medical Compression Systems, Inc, Or-Akiva, Israel) plus oral aspirin 81 mg daily for deep venous thrombosis (DVT) prophylaxis for 10 days.
On the first postoperative day, the drain was removed in all cases. In local infiltration analgesia patients, an additional 20 cc of 0.5% ropivacaine (100 mg) was infused through the intra-articular catheter, and the catheter was removed. Patients were mobilized by physical therapists on the first postoperative day for gait training, ROM, and quadriceps-strengthening exercises. Continuous passive motion was not used for any patient in either group.
Discharge criteria included the ability to walk with a walker or crutches for 50 feet, to get in and out of bed and on and off a toilet independently, and pain control with oral medications.
The primary outcome measure was the length of stay. Pain scores were recorded in the post-anesthesia care unit and with routine vital signs every 4 hours. Postoperative hematocrit, maximum temperature, and time that the patient remained in the post-anesthesia care unit were recorded and compared. To standardize pain scores, the 6 am pain score was used for comparison, since this was the time that patients were least likely to have had oral pain medications. All postoperative complications were noted.
A power analysis indicated that 34 patients were required in each group to detect a difference in the length of stay of 1 day with an alpha of 0.05 and beta of 0.80.
Student t test was used to compare continuous variables. Significance was defined as P<.05. Analyses were performed with Microsoft Excel 2010 (Microsoft Corporation, Redmond, Washington) and GraphPad (GraphPad Software, La Jolla, California).
The average length of stay was significantly lower in the local infiltration analgesia group compared to the control group (Table 1). Average postoperative hematocrit and time spent in the post-anesthesia care unit were similar for both groups.
Pain scores were recorded for the first 3 postoperative days unless they were discharged on postoperative day 2. There was a significant difference in average pain score on postoperative day 1, with the local infiltration analgesia score 1.6 points lower than the control group score (Table 2). There were no significant differences in average pain scores on postoperative day 2 or 3. The highest pain score was noted during the first 3 postoperative days. The average highest pain score was significantly higher for the control group than the local infiltration analgesia group.
No difference was noted in maximum postoperative temperature during the hospital stay.
Local infiltration analgesia patients who had undergone surgery earlier in the week (Monday/Tuesday; n=20) were compared to those who had undergone surgery later in the week (Thursday/Friday; n=20). Patients who had undergone surgery earlier in the week had a shorter average length of stay, and this difference was statistically significant (2.5±1.1 days for Monday/Tuesday vs 3.8±1.4 days for Thursday/Friday; P=.003). In the control group, however, there was no difference when comparing surgery early vs late in the week (3.8±1.7 days vs 3.8±1.0 days, respectively; P=.99).
In the control group, 2 patients required manipulation under anesthesia 7 and 8 weeks postoperatively. Additionally, 1 patient had a postoperative ileus prolonging his hospital stay to 7 days. Another patient developed atrial fibrillation with a rapid ventricular rate postoperatively, also prolonging his hospital stay to 7 days.
In the local infiltration analgesia group, 1 patient required manipulation under anesthesia at 12 weeks postoperatively. One patient required readmission for a superficial cellulitis that resolved with intravenous antibiotics without further sequelae. Another patient developed pneumonia postoperatively, requiring hospitalization and antibiotics (length of stay, 6 days), and 1 patient had a cerebrovascular accident postoperatively, secondary to a patent foramen ovale, prolonging his hospital stay to 7 days. No central nervous system or cardiac events from ropivacaine were observed in the local infiltration analgesia group.
Numerous pre- and intraoperative analgesic options exist, each with its own advantages and disadvantages. Neuraxial blockade (spinal or epidural analgesia) potentially decreases intraoperative blood loss and the need for transfusions postoperatively. Postoperative nausea, emesis, hypotension, poor muscle control, the need for an indwelling urinary catheter, and delayed physical therapy are possible drawbacks.3,6,14 With removal of an epidural catheter, the risk of an epidural hematoma in patients being treated with DVT chemoprophylaxis is real.6,15-18 Lumbar plexus blocks serve an alternative to neuraxial blockade, and it is safe in patients receiving DVT chemoprophylaxis, with a low risk of a psoas hematoma. Potential drawbacks with this technique include extension of the block into the epidural space and also include possible aorta or vena cava piercing.
Femoral nerve block is another regional analgesic modality that can be used pre- and intraoperatively. Proponents argue that femoral nerve block reduces intraoperative pain medications, reduces hospital stay, and may lead to earlier independent ambulation. However, Sharma et al19 cited patient falls with early mobilization, femoral neuritis, and cardiac dysrhythmias. Femoral nerve block can be done in a single shot or with a longer-term infusion catheter, typically of 24 to 48 hours, based on surgeon preferences. Sciatic nerve block has the same potential advantages and disadvantages as femoral nerve block, as it is also a peripheral nerve block. All of the above-described techniques are based on the operator as well, ie, proper needle placement avoids unintended infiltration, failure of blockade, and injection into adjacent vascular structures.20
Studies have demonstrated success with oral medications for perioperative analgesia. In 1 randomized controlled study, the use of celecoxib pre- and postoperatively along with patient-controlled analgesia had significantly better resting pain scores compared to a patient-controlled analgesia group alone.21 Another study by Clarke et al22 examined gabapentin and celecoxib pre- and postoperatively for 4 days and noted decreased patient-controlled analgesia use in the study group compared to a placebo group; all patients received femoral nerve block and sciatic nerve block. Improved active-assisted knee flexion was shown on postoperative days 2 and 3, but no difference in pain scores resulted.22 In a randomized, double-blind, placebo-controlled study, Lunn et al23 examined the analgesic effect of preoperative methylprednisolone in 24 patients undergoing TKA. One hundred twenty-five milligrams of intravenous methylprednisolone infusion in these patients resulted in lower C-reactive protein levels, less consumption of rescue narcotics, lower pain scores through 2 postoperative days, and less fatigue; no superficial or deep infections occurred.23
The drawbacks to our study include the historical group as a control and the lack of randomization. However, after initially using this local infiltration analgesia protocol and seeing the dramatic effect on pain relief provided by this technique, it would have been difficult to withhold this treatment for any patient. One local infiltration analgesia patient had a superficial incisional cellulitis, and this could have been due to the intra-articular catheter and the injection of ropivacaine on postoperative day 1. This was the only possible adverse reaction seen in a consecutive series of over 100 patients in whom this technique has been used at our hospital.
Pain relief is ideally administered in a form that prevents both intra- and postoperative pain to avoid pain hypersensitivity.24 Introducing an analgesic into the site of surgical trauma modifies the nervous system in 2 ways: (1) peripheral sensitization occurs by reducing the threshold for afferent nociceptive neurons, and (2) central sensitization occurs by increasing the excitability of spinal neurons.8
We injected a combination of ropivacaine, ketorolac, and epinephrine. Ropivacaine has a pharmacokinetic profile similar to bupivacaine with a longer half-life and lower cardiac and systemic toxicity; patients can therefore tolerate a higher dose.25 Ketorolac and other nonsteroidal anti-inflammatory drugs block the eicosanoid pathway and inflammatory cytokines as well as reducing peripheral sensitization of neurons.9 Epinepherine causes local vasoconstriction and aids in keeping the infiltrated drugs in the targeted environment to prevent higher plasma levels of the drug to prevent toxicity.
This local infiltration analgesia protocol resulted in a reduced length of stay that was statistically significant. A reduction in length of stay reduces acute care facility costs and reduces exposure to potential nosocomial infections. Our study was adequately powered, minimizing the possibility of alpha error. In addition, the study group also demonstrated reduced maximum pain scores and less pain on the first postoperative day, although the scores for day 2 and 3 were not different with local infiltration analgesia. Reduction in maximum pain scores overall could be due to desensitization of peripheral neurons, and thus there may be a lower baseline pain level.
We examined postoperative maximal temperatures because we hypothesized that fewer parenteral narcotics would lead to an improved pulmonary toilet, thereby reducing atelectasis and temperature elevations; however, no differences were seen.
Interestingly, local infiltration analgesia group patients who underwent surgery earlier in the week (Monday or Tuesday) went home earlier (statistically significant) than those who underwent surgery later in the week (Thursday or Friday). This is due to management of discharge due to social issues. The majority of our patients travel a significant distance to our facility and may not have transportation readily available over a weekend, or placement to a nursing facility was not possible over the weekend. We suspect that the length of stay would have been reduced further in the local infiltration analgesia group had these social issues not prevented timely discharge from the hospital.
Although variations exist among local infiltration analgesia protocols, published randomized trials have demonstrated a reduced need for patient-controlled analgesia,8 improved pain control,12 decreased narcotic consumption,13 and earlier mobilization.11 None of these studies had reported cardiac or central nervous system effects attributable to ropivacaine, nor did we encounter cardiovascular side effects from this analgesia technique. Bianconi et al25 demonstrated a shorter hospital length of stay, less postoperative pain at rest and with mobilization, fewer rescue medications, and nontoxic plasma concentrations of ropivacaine with a continuous infusion catheter in TKA and total hip arthroplasty (THA). Busch et al8 demonstrated improved patient satisfaction and fewer rescue medications in a randomized study of 64 patients. Kerr and Kohan26 showed that most patients could ambulate 5 to 6 hours postoperatively, with independent mobility at 13 to 22 hours, in a TKA and THA group of 325 patients. Parvataneni et al7 prospectively randomized 60 TKA patients into a control or periarticular injection study group. Excellent pain control and functional recovery were noted with a different intra-articular infiltration mixture: bupivacaine, morphine, epinephrine, methylprednisolone, cefuroxime, and normal saline. These studies indicate that a multimodal approach is clinically beneficial despite variations in technique.
One randomized trial compared a continuous infusion femoral nerve catheter to an local infiltration analgesia mixture similar to ours.27 They found more narcotic consumption in the local infiltration analgesia group within the first 48 hours postoperatively. Our comparative study addressed this by using a single-injection femoral nerve block. We do not anticipate that local infiltration analgesia will eliminate all periarticular pain; however, when local infiltration analgesia is used in conjunction with another preoperative analgesic modality (eg, single-injection femoral nerve block) there appears to be a synergistic, beneficial effect.
Only 1 other study in the literature examined the effect on length of stay in patients receiving local infiltration analgesia after TKA alone13; however, their study required a complex postoperative protocol consisting of a continuous intra-articular ropivacaine infusion, a 24-hour post-anesthesia care unit stay, scheduled 1 g acetaminophen every 6 hours, and scheduled intravenous 10 mg ketorolac. Their study did not involve a power analysis, introducing the possibility of alpha error. We believe our protocol is much simpler and practical, while focusing on cost savings as well.
Our results demonstrate that local infiltration analgesia is beneficial in reducing length of stay and postoperative pain scores. We recommend local infiltration analgesia in conjunction with a single-injection femoral nerve block as an alternative for the multimodal pain control approach in the TKA patient.
- Albert TJ, Cohn JC, Rothman JS, Springstead J, Rothman RH, Booth RE Jr. Patient-controlled analgesia in a postoperative total joint arthroplasty population. J Arthroplasty. 1991; (6 Suppl):S23-28.
- Franklin PD, Karbassi JA, Li W, Yang W, Ayers DC. Reduction in narcotic use after primary total knee arthroplasty and association with patient pain relief and satisfaction [published online ahead of print June 26, 2010]. J Arthroplasty. 2010; 25(6 Suppl):12-16.
- Singelyn FJ, Deyaert M, Joris D, Pendeville E, Gouverneur JM. Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty. Anesth Analg. 1998; 87(1):88-92.
- Serpell MG, Millar FA, Thompson MF. Comparison of lumbar plexus block versus conventional opioid analgesia after total knee replacement. Anaesthesia. 1991; 46(4):275-277.
- Allen HW, Liu SS, Ware PD, Nairn CS, Owens BD. Peripheral nerve blocks improve analgesia after total knee replacement surgery. Anesth Analg. 1998; 87(1):93-97.
- Horlocker TT, Hebl JR, Kinney MA, Cabanela ME. Opioid-free analgesia following total knee arthroplastya multimodal approach using continuous lumbar plexus (psoas compartment) block, acetaminophen, and ketorolac. Reg Anesth Pain Med. 2002; 27(1):105-108.
- Parvataneni HK, Shah VP, Howard H, Cole N, Ranawat AS, Ranawat CS. Controlling pain after total hip and knee arthroplasty using a multimodal protocol with local periarticular injections: a prospective randomized study [published online ahead of print July 26, 2007]. J Arthroplasty. 2007; 22(6 Suppl 2):33-38.
- Busch CA, Shore BJ, Bhandari R, et al. Efficacy of periarticular multimodal drug injection in total knee arthroplasty. A randomized trial. J Bone Joint Surg Am. 2006; 88(5):959-963.
- Essving P, Axelsson K, Kjellberg J, Wallgren O, Gupta A, Lundin A. Reduced morphine consumption and pain intensity with local infiltration analgesia (LIA) following total knee arthroplasty. Acta Orthop. 2010; 81(3):354-360.
- Essving P, Axelsson K, Kjellberg J, Wallgren O, Gupta A, Lundin A. Reduced hospital stay, morphine consumption, and pain intensity with local infiltration analgesia after unicompartmental knee arthroplasty. Acta Orthop. 2009; 80(2):213-219.
- Toftdahl K, Nikolajsen L, Haraldsted V, Madsen F, Tønnesen EK, Søballe K. Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial. Acta Orthop. 2007; 78(2):172-179.
- Venditolli PA, Makinen P, Drolet P, et al. A multimodal analgesia protocol for total knee arthroplasty. A randomized, controlled study. J Bone Joint Surg Am. 2006; 88(2):282-289.
- Gómez-Cardero P, Rodríguez-Merchán EC. Postoperative analgesia in TKA: ropivacaine continuous intraarticular infusion. Clin Orthop Relat Res. 2010; 468(5):1242-1247.
- Capdevila X, Barthelet Y, Biboulet P, Ryckwaert Y, Rubenovitch J, dAthis F. Effects of perioperative analgesic technique on the surgical outcome and duration of rehabilitation after major knee surgery. Anesthesiology. 1999; 91(1):8-15.
- Ben-David B, Rawa R. Complications of neuraxial blockade. Anesthesiol Clin North America. 2002; 20(3):669-693.
- Horlocker TT. When to remove a spinal or epidural catheter in an anticoagulated patient. Reg Anesth. 1993; 18(4):264-265.
- Horlocker TT, Wedel DJ. Anticoagulation and neuraxial block: historical perspective, anesthestic implications, and risk management. Reg Anesth Pain Med. 1998; 23(6 Suppl 2):129-134.
- Horlocker TT, Wedel DJ, Schlichting JL. Postoperative epidural analgesia and oral anticoagulant therapy. Anesth Analg. 1994; 79(1):89-93.
- Sharma S, Iorio R, Specht LM, Davies-Lepie S, Healy WL. Complications of femoral nerve block after total knee arthroplasty [published online ahead of print August 13, 2009]. Clin Orthop Relat Res. 2010; 468(1):135-140.
- Hogan MV, Grant RE, Lee L Jr. Analgesia for total hip and knee arthroplasty: a review of lumbar plexus, femoral, and sciatic nerve blocks. Am J Orthop (Belle Mead NJ). 2009; 38(8):E129-E133.
- Huang YM, Wang CM, Wang CT, Lin WP, Horng LC, Jiang CC. Perioperative celecoxib administration for pain management after total knee arthroplastya randomized, controlled study. BMC Musculoskelet Disord. 2008; (9):77.
- Clarke H, Pereira S, Kennedy D, et al. Gabapentin decreases morphine consumption and improves functional recovery following total knee arthroplasty. Pain Res Manag. 2009; 14(3):217-222.
- Lunn TH, Kristensen BB, Andersen LØ, et al. Effect of high-dose preoperative methylprednisolone on pain and recovery after total knee arthroplasty: a randomized, placebo-controlled trial [published online ahead of print December 3, 2010]. Br J Anaesth. 2011; 106(2):230-238.
- Badner NH, Bourne RB, Rorabeck CH, MacDonald SJ, Doyle JA. Intra-articular injection of bupivacaine in knee-replacement operations. Results of use for analgesia and for preemptive blockade. J Bone Joint Surg Am. 1996; 78(5):734-738.
- Bianconi M, Ferraro L, Traina GC, et al. Pharmacokinetics and efficacy of ropivacaine continuous wound instillation after joint replacement surgery. Br J Anaesth. 2003; 91(6):830-835.
- Kerr DR, Kohan L. Local infiltration analgesia: a technique for the control of acute postoperative pain following knee and hip surgery: a case study of 325 patients. Acta Orthop. 2008; 79(2):174-183.
- Carli F, Clemente A, Asenjo JF, et al. Analgesia and functional outcome after total knee arthroplasty: periarticular infiltration vs continuous femoral nerve block [published online ahead of print June 14, 2010]. Br J Anaesth. 2010; 105(2):185-195.
Drs Tripuraneni, Woolson, and Giori are from the Department of Orthopedic Surgery, Stanford University, Stanford, and Palo Alto Veterans Administration Hospital, Palo Alto, California.
Drs Tripuraneni, Woolson, and Giori have no relevant financial relationships to disclose.
Correspondence should be addressed to: Steven T. Woolson, MD, Palo Alto Veterans Administration Hospital, 3801 Miranda Ave, Palo Alto, CA 94303 (email@example.com).