What's New in Adult Reconstructive Knee Surgery.

Abstract

The COVID-19 pandemic has inflicted challenges that have affected every facet of our personal and professional lives1,2. During this time, the orthopaedic community has demonstrated resilience, persistence, and innovation in providing care to our patients3. We are called to redouble our efforts as knee arthroplasty surgeons to continue to provide safe and efficient value-driven care. Osteoarthritis of the Knee: Nonsurgical Management As the incidence of knee osteoarthritis (OA) increases4, patient wait times continue to increase for arthroplasty. For 12% of these patients in 1 recent study, their health (as measured by the EuroQol 5-Dimension [EQ-5D]) was actually “worse than death.”5 However, in a separate report, patients receiving physical therapy in the setting of knee OA, involving exercise and manual therapy, received benefit at 1 year (90% attained the minimally clinical important difference [MCID] in the Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] score)6. If patients with obesity and diabetes7 begin intensive lifestyle changes before experiencing knee pain, some can prevent the need for total knee arthroplasty (TKA): 29% in 1 recent report8. Considerable debate continues to exist regarding the effectiveness of platelet-rich plasma, stem cell, and hyaluronic acid injections9,10. Operative Management: Non-Arthroplasty Options High Tibial Osteotomy With the availability of reliable arthroplasty options for unicompartmental OA, the decision for high tibial osteotomy (HTO) continues to be under increased scrutiny. A meta-analysis found a rate of conversion to TKA of 13% at a mean of 71 months11. In a prospective comparative study, at 2 years, the rate of return to sport was 94.1% in a unicompartmental knee arthroplasty (UKA) group compared with 74.0% in the HTO group (p = 0.031)12. Conversion from UKA or HTO to TKA leads to longer operative time and an increased utilization rate of revision implants than with primary TKA (96.1 versus 90.0 minutes [p = 0.01]; and 8.5% versus 0.8% [p = 0.005], respectively)13. Risk and Health Policy To ensure fiscal soundness in orthopaedic practice, a complete understanding of cost variation will assist in appropriate risk adjustment for reimbursement in alternative payment models, which is critically important for orthopaedic practice in the U.S. Currently, the only risk adjustment provided for primary TKA has been the 469 DRG (Diagnosis-Related Group) code. Ryan et al. found that 17 comorbidities are predictive of increased cost for the TKA episode, but only 4 of them are predictive of MS (Medicare Severity)-DRG classification14. For the initial in-hospital costs during TKA, another recent study found that characteristics of the surgical episode (implants, operating room time, etc.) accounted for 35.3% of cost variation. Patient characteristics were markedly associated with discharge disposition15. In addition, an age of ≥72 years and increasing modified frailty index (mFI) score were associated with increased cost16. Furthermore, as the U.S. Centers for Medicare & Medicaid Services (CMS) has removed TKA from the Inpatient Only (IPO) list, a much larger number of those patients are now classified as “outpatient.” CMS has excluded outpatients from the CMS bundled-payment programs. This has led to confusion among surgeons and health-care systems. Without any change in quality, many programs have seen increased mean costs in their bundled-payment program, leading to financial loss17. This requires further intervention and guidelines by CMS to head off the negative implications of removing TKA from the IPO list. UKA Outcomes and Design As modern UKA implant designs mature, better long-term data emerge. The pooled 5 and 10-year survivorship of medial UKA in a meta-analysis of 26 studies was 95.3% and 91.3%, respectively18. Additionally, the presence of patellofemoral OA did not appear to affect the outcome of fixed-bearing UKA19. In a retrospective study of 308 medial UKAs performed with fixed-bearing components, the presence of patellofemoral OA at the time of surgery did not affect the all-cause revision rate (98% with patellofemoral OA compared with 99.5% without patellofemoral OA; p = 0.352), or the Forgotten Joint Score (FJS) at 5 years (71 with patellofemoral OA compared with 77 without; p = 0.270)20. Age, body mass index (BMI), and duration of symptom onset before UKA may affect the FJS21. Surprisingly, high activity did not appear to affect survivorship at 9 years22. Cementless UKA In an independent report from the United Kingdom, cementless UKA demonstrated success at 5 years comparable to that of UKA with cemented fixation, with a survivorship of 97.4% and an Oxford knee score of 4323. However, some early subsidence of the tibial component remains a concern23-25. Mohammad et al. reported the 10-year all-cause survivorship of the first 1,000 developer-implanted cementless Oxford UKAs, at 96.6%26. Robotic-Assisted UKA A purported benefit of robotic-assisted UKA is improved accuracy. However, a recent report found that, at least for an experienced surgeon, the accuracy of tibial placement is similar to that previously reported for mechanical tibial alignment27. This is reflected in a recent report using data from the Australian Orthopaedic Association National Joint Replacement Registry. At a follow-up of 1, 2, and 3 years, there was no difference in revision rates when comparing robotic-assisted fixed-bearing UKA and another popular fixed-bearing UKA with standard instrumentation: 1.5% compared with 1.4%, 2.3% compared with 2.7%, and 2.6% compared with 3.7%, respectively28. In comparison, another group found that, at 5 years, the survivorship of robotic arm-assisted medial UKA was 98.4% with use of an onlay design. However, it is important to note the effect of BMI, with a survivorship of 99.1%29 among patients with a BMI of <30 kg/m2. UKA Compared with TKA The results of the Total or Partial Knee Arthroplasty Trial (TOPKAT), a multicenter pragmatic randomized controlled trial (RCT) comparing UKA and TKA for the treatment of medial compartment OA, were recently reported; a variety of implants were used30. At the 5-year follow-up, there was no difference in Oxford knee scores, but UKA was more cost-effective and provided an additional 0.24 quality-adjusted life year. In a separate report, patients who underwent UKA were less likely to need continued narcotics requiring a refill than those who underwent TKA (odds ratio [OR], 0.58; p = 0.001)31. Surgeons should decrease the number of narcotic pills after UKA accordingly. However, there appears to be a price to pay with regard to revision risk; TKA converted from medial UKA had a higher risk of revision (adjusted hazard ratio [HR], 3.00) when compared with primary TKA32. TKA: Perioperative Risk Stratification, Readmission, and Minimizing Complications A retrospective review of an administrative database of primary total joint arthroplasty (TJA) procedures revealed that 21% of the patients received a gabapentinoid (gabapentin or pregabalin) on the day of surgery. In a multilevel regression analysis, the receipt of a gabapentinoid at any dose was associated with increased odds of postoperative pulmonary complications (OR, 1.81) in a dose-response fashion33. Additionally, there was no apparent reduction in opioid consumption. With the increasing push for a short stay for primary TKA, the case for identification of perioperative risk, perioperative optimization, and coordination of care strengthens. Patients who have a postoperative medical complication after TKA appear to be at a substantially increased risk of having the same complication again after TKA for the contralateral knee. For instance, in 1 recent study, the risk of repeat myocardial infarction demonstrated an OR of 56.63 (p < 0.001)34. The implementation of a “perioperative orthopaedic surgical home” led to a lower 30-day readmission rate (1.6% versus 5.3%; p = 0.03) in a retrospective study of 4,188 TKA patients35. Malnutrition is a serious medical condition prior to TKA. When malnourished patients were treated with a high-protein diet prior to TKA, they had a shorter hospital length of stay (p = 0.04), lower global charges, and lower readmission rates (p < 0.001) than did patients not treated for malnourishment36. In another study, TKA patients with anemia had an increased risk of any postoperative complication (OR, 5.186; p < 0.001)37. Patients undergoing primary TKA with a history of periprosthetic joint infection (PJI) in another joint demonstrated a significantly higher risk of PJI after the primary TKA than found for a matched cohort without a history of PJI (6.1% compared with 2.6% at 10 years; HR, 3.3; p = 0.02)38. Patients with a high blood fructosamine level preoperatively were noted to be 11.2 times more likely to develop PJI when compared with those with a normal value (p = 0.001)39. Anesthesia and Pain Management Spinal anesthesia, when compared with general anesthesia, was associated with fewer 30-day complications and a lower likelihood of a non-home discharge (p < 0.05) in a retrospective review of TJA data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database40. A retrospective observational study of >3,900 patients undergoing primary TKA or total hip arthroplasty (THA) demonstrated that, after multivariable logistic regression, patients who received general anesthesia had an OR for PJI of 2.0 compared with propensity score-matched patients who received spinal anesthesia41. In revision TKA, the risks of unplanned readmission, non-home discharge, transfusion, deep surgical site infection (SSI), and extended length of stay were all greater after general anesthesia compared with spinal anesthesia (OR, 1.22 to 1.63; p < 0.001) according to a study by Wilson et al.42. One week after TKA, patients who received spinal anesthesia scored significantly higher on the Mini-Mental State Examination compared with those who received general anesthesia in a recent prospective RCT43. However, rapid recovery protocols may reduce the increased risk of general anesthesia, with a low readmission rate (2.4%) and reoperation rate (1.3%) noted in 1 recent study44. When compared with propofol, intraoperative use of dexmedetomidine resulted in lower postoperative opioid requirements 0 to 48 hours postoperatively (135 versus 360 μg; p = 0.003)45. Patients who received intravenous dexamethasone at the time of TKA had less pain in the first 24 hours postoperatively in a double-blinded, placebo-controlled RCT46. Additionally, the postoperative application of a nonsteroidal patch containing flurbiprofen led to decreased pain in the first 3 postoperative days and better range of motion at 1 to 2 weeks in a prospective RCT47. Regional Blocks Two recent studies demonstrated that an adductor canal block provided equivalent pain relief to a continuous femoral nerve block, while providing improved functional function postoperatively48,49. In a blinded RCT, a single-injection adductor block provided the same pain relief and improved postoperative strength compared with an indwelling block50. However, a recent meta-analysis indicated lower pain scores (p < 0.0001), morphine consumption (p = 0.003), and hospital length of stay (p = 0.03) with an indwelling block51. An additive effect for pain and opioid use reduction was demonstrated when adding a periarticular block to a femoral nerve or adductor canal block52. A periarticular block alone may provide improved pain relief compared with an adductor canal block immediately postoperatively, as assessed at 6, 12, and 24 hours postoperatively after unilateral TKA53. Early postoperative pain relief was improved when a saphenous nerve block was added to a standard periarticular block in a prospective RCT54 . However, early pain relief was not improved with the addition of a block of the interspace between the popliteal artery and capsule of the knee (IPACK block)55, or liposomal bupivacaine56. Opioid Pain Medications Given the ongoing opioid crisis, arthroplasty surgeons should maintain vigilance in prescribing practices. A recent award-winning RCT demonstrated that the reduction of oxycodone prescribed at discharge by sixty 5-mg pills led to similar pain scores, no changes in outcomes, and an overall reduction in the pain pills taken by an average of 300 morphine milligram equivalents (MMEs) (p < 0.001)57. Patient requests for a refill have led to the practice of prescribing larger quantities of opioids. However, the authors of 1 recent study found that the MMEs given at discharge did not correlate with refill requests (p = 0.21), while increased pain on postoperative day 1 (p < 0.001) and younger age (p = 0.003) did correlate58. TKA: Intraoperative Surgical Technique for TKA Intraoperative techniques that may improve early functional outcome are always a hot topic. The use of subcuticular sutures or use of skin adhesive have the highest patient satisfaction, with no increase in SSI, according to a Cochrane systematic review59. The operative time for TKA was associated with an increase in the risk of SSI and PJI, even after multivariate analysis. In cases that lasted >121 minutes, the risk of PJI was 1.4%, compared with 0.3% for those of <85 minutes (p < 0.001)60. A systematic review provided moderate evidence that there is no significant difference in the overall complication rate of simultaneous bilateral TKA compared with staged bilateral TKA61. Weakness of the quadriceps and increased pain have been cited as reasons for discontinuing the routine use of a tourniquet during TKA. However, recent studies may contradict that thinking62-64. Goel et al. found that TKA without tourniquet use had, on average, >180 mL of additional blood loss (p < 0.001), with no improvement in visual analog scale (VAS) pain scores or the Timed Up & Go test in a well-organized prospective RCT63. However, other recent studies have shown markedly reduced blood loss with or without a tourniquet when tranexamic acid (TXA) was used65,66. The technique for balancing the soft tissues and determining optimal alignment during TKA is widely debated. A recent prospective randomized study comparing “gap balancing” and “measured resection” techniques during simultaneous bilateral TKA found no difference in function or patient-reported outcome measures (PROMs) at 2 years67. However, there were more medial releases in extension, significantly more bone removed, and smaller femoral components in the gap balancing group. A prospective RCT comparing kinematic alignment and mechanical alignment in simultaneous bilateral TKA found that the mechanically aligned knees required more soft-tissue releases (p = 0.018), while patients preferred a kinematically aligned TKA more often (p = 0.03)68. Another RCT comparing alignment techniques found no difference in Oxford knee score (kinematic alignment, 41.4, and mechanical alignment, 41.7; p = 0.99) or survivorship at 5 years (mechanical, 94.1%, and kinematic, 95.9%; p = 0.681)69. However, there has been concern that the varus tibial cut in kinematically aligned knees could lead to component migration and failure. A recent radiostereometric analysis in an RCT found no difference in component migration at 2 years among 47 patients70. Technology-Assisted TKA Precision alignment of TKA is a worthy goal; however, the exact target remains somewhat elusive. Recent meta-analyses of studies comparing alignment techniques found no difference in functional outcomes at 6 months between mechanical and computer-navigated alignment71, and no difference in aseptic loosening or revision with mid-term follow-up, despite more precise alignment in navigated72 (aseptic loosening relative risk [RR], 0.78), robotic (Kaplan-Meier survivorship, 98% at 15 years; p = 0.972)73, and patient-specific instrumentation (PSI) TKA74,75. Outcomes There is a vast array of factors that affect the outcome of TKA. A majority of these factors may be unique to the patient. Patients with severe contralateral knee pain may be less satisfied with their TKA (OR, 0.57; p = 0.002)76. Patients who are psychologically distressed prior to TKA may expect similar rates of satisfaction and fulfillment of expectations compared with non-distressed TKA patients77. Smoking tobacco is an independent risk factor for inferior patient-reported outcomes after TKA and appears to be dose-dependent. One study found that 82% of smokers were satisfied with their TKA compared with 89% of nonsmokers (p = 0.05)78. Acquired idiopathic stiffness after primary TKA is defined by a postoperative range of motion of <90°, persisting for >3 months after TKA. Female patients and patients who are obese have a higher risk than their counterparts of acquiring this complication (3% versus 1% [p < 0.0001], and 5% versus 2% [p = 0.027], respectively79. Implant Design Highly cross-linked polyethylene bearings appear to afford no improvement in revision rates in primary TKA. The adjusted HR for all-cause revision of TKA with standard cross-linked polyethylene ranged from 0.8 to 1.2 (p = 0.1 to p = 0.5) for 3 major implant designs80. Vitamin E-stabilized polyethylene did demonstrate reduced oxidation at the articulating surface and backside surface at an average of 1.2 years in a retrieval study81. All-polyethylene tibial components, when evaluated for subsidence on radiostereometric analysis, demonstrated no increase in component migration compared with a metal-backed implant at 2 years82. Cementless TKA Cementless fixation in primary TKA has the potential for improved durability and long-term fixation and possible utilization in the allergic patient83, at the historical cost of inferior rates of early revision for aseptic loosening. A recently reported RCT found that hybrid fixation (cemented tibia, uncemented femur) in TKA had a similar 13-year survivorship (98%) to that of cemented fixation84. In recent prospective randomized trials of cementless versus cemented fixation, there was no difference in revision or clinical outcome measurements out to 2 years85,86. Additionally, the operative time of cementless TKA was shorter, with no difference in postoperative hemoglobin values86. The Patella in Primary TKA Surgeons who selectively resurface the patella can expect a 4-times higher risk of patellar revision than surgeons who routinely resurface the patella, according to an analysis of data from the Australian Orthopaedic Association National Joint Replacement Registry87. In a prospective randomized clinical trial of 60 patients undergoing bilateral simultaneous TKA, 47% of the patients preferred the knee with a resurfaced patella compared with 7%, the non-resurfaced side88. Meta-analyses also found an increased risk of revision if the patella is left non-resurfaced, with a number needed to treat of 25 to avoid 1 case of reoperation89, and an OR for reoperation of 3.2490. This may, however, reflect the fact that revision of the patella is something that can be done for a patient who has an unsatisfactory outcome following primary TKA. TKA: Postoperative Recovery, Discharge Readiness, and Rehabilitation A number of interventions have been found to be effective in improving early recovery, and 2020 has identified a few more. Patients given 10 mg of dexamethasone intravenously 1 hour prior to surgery and 0.2 mg/kg at 24 hours postoperatively experienced less pain and nausea than a control group (p < 0.01)91. The use of essential amino acid supplementation in the perioperative period appeared to prevent atrophy of the rectus femoris and improve recovery of activities of daily living after primary TKA in a double-blinded, placebo-controlled randomized trial92. When patients were randomized to receive physical therapy on the day of surgery rather than on postoperative day 1, there was no demonstrated decrease in overall length of stay or satisfaction93. Compared with a traditional outpatient physical therapy program, a virtual rehabilitation program was associated with equivalent clinical outcomes and lower cost after primary TKA (median, $1,050 versus $2,805 [USD] at 12 weeks; p < 0.001)94. For younger patients who plan to return to work, patient-specific activity-related goal rehabilitation led to significantly improved patient satisfaction at 1 year postoperatively95. Outpatient TKA When considering the results of outpatient TKA, most patients selected for it are younger, more active, and less medically complex than those selected for inpatient TKA. A recent systematic review reported the outcome of outpatient TKA among 19 studies comprising 6,519 procedures. The same-day discharge rate was 93.4%, with a 90-day readmission rate of 2.3%96. However, it is important to note the increased demand on the surgical service, with 1 study noting an average of 48.4 minutes of patient contact in the postoperative period after outpatient TKA97. Furthermore, there is a desire to broaden the cohort that may undergo outpatient TKA, especially in the era of COVID-1998. The Outpatient Arthroplasty Risk Assessment (OARA) score is intended to identify patients who can safely undergo outpatient TKA. A score value of ≤79 demonstrated a 98.8% positive predictive value for outpatient discharge99. Thromboembolic Prophylaxis rA recent systematic review and meta-analysis of RCTs focused on the effectiveness of aspirin (acetylsalicylic acid [ASA]). This study found that the relative risk of venous thromboembolism (VTE) with the use of ASA for prophylaxis was not significantly different than that of rivaroxaban (RR, 1.52; 95% confidence interval, 0.56 to 4.12)100. Additionally, in 6,078 patients, the rate of VTE and pulmonary embolism with ASA was 1.11%, and is comparable with results of other anticoagulants that are more expensive and with higher risk of bleeding complications101. Outcomes of Primary TKA in Obese Patients The risk of complications after TKA among those with morbid obesity is well established. Even a loss of 20 lb (9.1 kg) prior to TKA is associated with a shorter hospital stay (mean difference, −0.87 day; p = 0.001), according to Keeney et al.102. Boyce et al., in a systematic review, reported a TKA revision rate of 7% for morbidly obese patients compared with 2% for those who were non-obese (p < 0.001)103. However, morbidly obese patients do experience clinical improvements after TKA104, and withholding arthroplasty may not be the solution to avoiding complications. One study found that restricting TKA for morbidly obese patients led to >70% of the patients ultimately not having surgery. Only 40% of those who did undergo surgery ultimately achieved a BMI of <40 mg/m2 at surgery105. Correcting other medical conditions associated with morbid obesity may be more important than obesity itself. Sloan et al. performed an NSQIP database review and found that hypoalbuminemia led to an increased risk of readmission (OR, 1.62; p < 0.001) and reoperation (OR, 1.52; p = 0.001) within 30 days, more so than all classes of obesity106. Infection Because of the number of patients needed to adequately power studies of infection, the effectiveness of prophylactic measures is difficult to determine. A recent prospective RCT was stopped early because there was only 1 infection among 179 patients in the control group of Staphylococcus aureus-positive patients being studied for the effectiveness of a decolonization protocol107. Antibiotic-loaded cement (ALBC) in TKA is still debated regarding the risk of septic revision. Jameson et al. found a decreased risk of infection with ALBC (HR, 0.85; p < 0.001) in a registry review of 713,214 TKAs108. Chan et al. found, in a nationwide database review, decreased odds of infection (OR, 0.89) but increased odds of acute kidney injury (OR, 1.06) with ALBC109. Anis et al., however, found no significantly decreased odds of infection in 12,541 primary TKAs (OR, 1.4; p = 0.133)110. In a cost analysis, Yayac et al. found that, to justify the increased cost of ALBC, 1 infection in 101 patients would need to be prevented111. In those with an infection, appropriate treatment can mean a notable difference with respect to morbidity and mortality. However, even with appropriate care, patients who require a spacer exchange during the course of a 2-stage treatment of PJI in TKA have an increased risk of failure of infection treatment112. Yang et al. found that patients who continued microorganism-directed oral antibiotics after 2-stage reimplantation had a significantly lower rate of treatment failure due to further infection compared with those who did not (12.5% compared with 28.6%; p = 0.012)113. However, readers should note that the rate of reinfection was much higher overall in this study than many other reports in the literature. Revision TKA In a review of a modern series of revision TKA, the risk of re-revision of TKA in patients ≤50 years of age was 32% at 10 years postoperatively114. To help avoid re-revision for aseptic loosening, metaphyseal fixation has become common practice, especially in cases of substantial bone loss115. At 2.4 years, survivorship free of metaphyseal cone revision was 98% in a group of 142 revision TKAs with mostly Type-2B and 3 defects116. However, in hinged TKA, with increased stress at the bone-implant interface, there was a 16% revision rate at 10 years for aseptic loosening117. Evidence-Based Orthopaedics The editorial staff of JBJS reviewed a large number of recently published studies related to the musculoskeletal system that received a higher Level of Evidence grade. In addition to articles cited already in this update, 13 other articles with a higher Level of Evidence grade were identified that are relevant to adult reconstructive knee surgery. A list of those titles is appended to this review after the standard bibliography. We have provided a brief commentary about each of the articles to help guide your further reading, in an evidence-based fashion, in this subspecialty area. Evidence-Based Orthopaedics Agarwal N, To K, McDonnell S, Khan W. Clinical and radiological outcomes in robotic-assisted total knee arthroplasty: a systematic review and meta-analysis. J Arthroplasty. 2020 Mar 11. [Epub ahead of print]. This meta-analysis found that robotic-assisted TKA provided superior WOMAC and Hospital for Special Surgery scores compared with conventional TKA. The authors discuss that the improvement in postoperative alignment of the knee in robotic-assisted TKA may be the determinant of these improved outcomes. Amit P, Singh N, Soni A, Bowman NK, Maden M. Systematic review of modular bicompartmental knee arthroplasty for medio-patellofemoral osteoarthritis. J Arthroplasty. 2020 Mar;35(3):893-899.e3. Epub 2019 Oct 8. In a systematic review of 9 studies that included 229 patients who received bicompartmental knee arthroplasty (BCKA) and 102 patients who underwent TKA, the authors note improved range of motion and FJS at short-term follow-up for BCKA. However, this is at the cost of the survivorship of BCKA: 58% at 17 years of follow-up. Berenbaum F, Blanco FJ, Guermazi A, Miki K, Yamabe T, Viktrup L, Junor R, Carey W, Brown MT, West CR, Verburg KM. Subcutaneous tanezumab for osteoarthritis of the hip or knee: efficacy and safety results from a 24-week randomised Phase III study with a 24-week follow-up period. Ann Rheum Dis. 2020 Jun;79(6):800-10. Epub 2020 Mar 31. Patients with knee OA who cannot tolerate or who have not responded to anti-inflammatories may benefit from the nerve growth factor inhibitor tanezumab. This was a blinded randomized study with 849 patients with OA. The authors noted improvement from baseline for tanezumab 5 mg compared with placebo in the WOMAC physical function and the Patient’s Global Assessment of OA (PGA-OA) at 24 weeks (−0.71 [p < 0.0001] and −0.19 [p = 0.0051], respectively). Calkins TE, Culvern C, Nam D, Gerlinger TL, Levine BR, Sporer SM, Della Valle CJ. Dilute Betadine lavage reduces the risk of acute postoperative periprosthetic joint infection in aseptic revision total knee and hip arthroplasty: a randomized controlled trial. J Arthroplasty. 2020 Feb;35(2):538-543.e1. Epub 2019 Sep 12. This RCT found that patients randomized to receive dilute Betadine lavage prior to closure in revision TKA had reduced risk of infection when compared with saline solution (0.4% versus 3.4%; p = 0.038). Fillingham YA, Hannon CP, Erens GA, Hamilton WG, Della Valle CJ; AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup. Acetaminophen in total joint arthroplasty: the clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society. J Arthroplasty. 2020 Oct;35(10):2697-9. Epub 2020 May 26. This clinical practice guideline discusses evidence-based usage of acetaminophen during the perioperative period of TJA. There is a moderate recommendation that acetaminophen reduces pain and opioid consumption during the perioperative period, and consensus agreement that it is a useful component of a postoperative pain-control regimen. Additionally, there is a strong recommendation that acetaminophen does not increase complications after TKA. Fillingham YA, Hannon CP, Roberts KC, Hamilton WG, Della Valle CJ; AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup. Nonsteroidal anti-inflammatory drugs in total joint arthroplasty: the clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society. J Arthroplasty. 2020 Oct;35(10):2704-8. Epub 2020 May 29. This clinical practice guideline discusses evidence-based usage of nonsteroidal anti-inflammatory drugs (NSAIDs) during the perioperative period of TJA. There is a strong recommendation that oral and intravenous NSAIDs reduce pain and opioid consumption during the perioperative period, and a moderate recommendation that they are a useful component of a postoperative pain-control regimen. Additionally, there is a limited recommendation that NSAIDs do not increase complications after TKA; however, surgeons should consider the route of administration and patient comorbidities when prescribing NSAIDs. Hannon CP, Fillingham YA, Browne JA, Schemitsch EH, Buvanendran A, Hamilton WG, Della Valle CJ; AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup. Gabapentinoids in total joint arthroplasty: the clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society. J Arthroplasty. 2020 Oct;35(10):2700-3. Epub 2020 May 26. This clinical practice guideline discusses evidence-based usage of gabapentinoids during the perioperative period of TJA. There is a strong recommendation that gabapentinoids do not reduce pain and opioid consumption during the perioperative period, but pregabalin does reduce opioid consumption. There is a strong recommendation that pregabalin may reduce postoperative pain and opioid consumption, but gabapentin does not. Hannon CP, Fillingham YA, Nam D, Courtney PM, Curtin BM, Vigdorchik JM, Buvanendran A, Hamilton WG, Della Valle CJ; AAHKS Anesthesia & Analgesia Clinical Practice Guideline Workgroup. Opioids in total joint arthroplasty: the clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Society of Regional Anesthesia and Pain Medicine, American Academy of Orthopaedic Surgeons, Hip Society, and Knee Society. J Arthroplasty. 2020 Oct;35(10):2709-14. Epub 2020 May 26. This clinical practice guideline discusses evidence-based usage of opioids during the perioperative period of TJA. There is a moderate recommendation that preoperative opioids may lead to inferior PROMs, an increase in opioid requirement postoperatively, and increased numbers of complications after TKA. There is a limited recommendation that the reduction of preoperative opioid use could lead to improved postoperative outcomes. There is a strong recommendation that opioid administration prior to TJA may increase the risk of complications, but with reduced postoperative pain. There is a moderate recommendation that reducing the number of opioid pills dispensed at discharge may improve outcomes after TKA. Joseph MN, Achten J, Parsons NR, Costa ML; PAT Trial Collaborators. The PAT randomized clinical trial. Bone Joint J. 2020 Mar;102-B(3):310-8. The WOMAC function score revealed no difference in outcome between patellofemoral arthroplasty and TKA at 12 months (adjusted mean difference, −1.2; p = 0.765) in this double-blinded RCT. Ma HH, Chou TA, Tsai SW, Chen CF, Wu PK, Chen WM. The efficacy of continuous versus single-injection femoral nerve block in total knee arthroplasty: a systematic review and meta-analysis. BMC Musculoskelet Disord. 2020 Feb 24;21(1):121. This meta-analysis found that a continuous femoral nerve block was associated with a lower consumption of postoperative opioids compared with a single-injection femoral nerve block after primary TKA at 24 hours (standardized mean difference [SMD], −1.056) and 48 hours (SMD, −1.040). Refsum AM, Nguyen UV, Gjertsen JE, Espehaug B, Fenstad AM, Lein RK, Ellison P, Høl PJ, Furnes O. Cementing technique for primary knee arthroplasty: a scoping review. Acta Orthop. 2019 Dec;90(6):582-9. Epub 2019 Aug 27. In a review of 57 studies, the authors found that pulsatile lavage irrigation, drying the bone, and drilling holes in the tibial surface was the favored technique in TKA cementation. Yang X, Kang W, Xiong W, Lu D, Zhou Z, Chen X, Zhou X, Feng X. The effect of dexmedetomidine as adjuvant to ropivacaine 0.1% for femoral nerve block on strength of quadriceps muscle in patients undergoing total knee arthroplasty: a double-blinded randomized controlled trial. J Pain Res. 2019 Dec 17;12:3355-63. The authors of this double-blinded RCT found that the addition of dexmedetomidine to 0.1% ropivacaine for patients undergoing TKA provided improved postoperative quadriceps muscle strength by the Timed Up & Go test (p < 0.05), with corresponding lower pain scores at 24 and 48 hours compared with low-dose and high-dose ropivacaine alone (p < 0.05). Zhang Y, Liu L, Zheng L, Chen J, Huang L, Wang Q, Shi K. Comparison of effectiveness of ropivacaine infusion regimens for continuous femoral nerve block for recovery after total knee arthroplasty: a randomized double-blind trial. J Pain Res. 2020 May 12;13:997-1005. The authors of this double-blinded randomized trial concluded that a continuous femoral nerve block with 0.15% ropivacaine provided the best combination of discharge timing and quadriceps muscle strength when compared with 0.1% and 0.2% ropivacaine.