Aims. The aim of this study was to determine the general postoperative opioid consumption and rate of appropriate disposal of excess opioid prescriptions in patients undergoing primary unilateral total knee arthroplasty (TKA). Patients and Methods. In total, 112 patients undergoing surgery with one of eight arthroplasty surgeons at a single specialty hospital were prospectively enrolled. Three patients were excluded for undergoing secondary procedures within six weeks. Daily pain levels and opioid consumption, quantity, and disposal patterns for leftover medications were collected for six weeks following surgery using a text-messaging platform. Results. Overall, 103 of 109 patients (94.5%) completed the daily short message service (SMS) surveys. The mean oral morphine equivalents (OME) consumed during the six weeks post-surgery were 639.6 mg (. sd. 323.7; 20 to 1616) corresponding to 85.3 tablets of 5 mg oxycodone per patient. A total of 66 patients (64.1%) had stopped taking opioids within six weeks of surgery and had the mean equivalent of 18 oxycodone 5 mg tablets remaining. Only 17 patients (25.7%) appropriately disposed of leftover medications. Conclusion. These prospectively collected data provide a benchmark for general opioid consumption after uncomplicated primary unilateral TKA. Many patients are prescribed more opioids than they require, and leftover medication is infrequently disposed of appropriately, which increases the risk for illicit diversion. Cite this article: Bone Joint J 2019;101-B(7 Supple C):98–103

Introduction. Over the past few decades, opioid abuse has become a major threat to public health. In 2013 alone, enough opioid prescriptions were written in the United States for every American adult to have their own bottle of pills. Since then, opioid prescribing rates and opioid related deaths have continued to grow, with over 46 people dying on average each day from prescription opioid overdoses in 2016. Orthopaedic surgeons are among the top 5 specialties in the number of opioid prescriptions written. For many common surgeries, such as total knee arthroplasty (TKA), post-discharge prescriptions are based on prescriber habits and opinion. There exists limited data-driven protocols to guide post-operative opioid prescribing practices. The purpose of this prospective study was to determine the average postoperative opioid consumption in patients undergoing primary TKA using a novel mobile text messaging platform. We hypothesized that majority of patients undergoing TKA do not properly dispose of left over pills after surgery. Methods. 95 patients undergoing primary unilateral TKA with one of nine arthroplasty surgeons at a single orthopaedic specialty hospital were prospectively enrolled. Daily pain levels and opioid consumption, and quantity and disposal patterns for left over medications were collected for six weeks following surgery using a novel mobile phone text messaging system. This system automatically queried patients twice a day, storing responses on a secure third-party host that investigators monitored and used to generate data reports in real-time. Results. Of the 95 patients enrolled, 1 was excluded for undergoing a secondary procedure in the acute postoperative data collection period. Of the remaining 94 patients, 88 (93.6%) completed the daily SMS surveys and were included in analysis. Average age was 62.0 ± 7.1 years, BMI 31.1 ± 6.2, and length of hospital stay 2.6 ± 1.2 days. The average oral morphine equivalents (OME) consumed during the 6 weeks post-surgery were 617.3 ± 350.26 mg, which corresponds to a mean consumption of 82 oxycodone 5 mg tablets per patient. For the 55(58.5%) of patients who had stopped taking opioids within 6 weeks of surgery, there were on average 196.2 mg OME left over, the equivalent of 26 oxycodone 5 mg tablets; 20% of those who stopped taking opioids had at least 367.5 mg OME left over, the equivalent of at least 49 oxycodone 5 mg tablets. Only 26.5% of patients with left over pills described an appropriate method of disposal of left over medications, with most patients storing left over pills in their homes. Conclusion. This prospectively collected data provides a benchmark for average opioid consumption after uncomplicated primary unilateral TKA. Many patients are prescribed more opioids than they require, and left-over medication is infrequently disposed of appropriately, which increases the risk for illicit diversion. Prospective collection of patient reported opioid consumption has tremendous value in the development of national postoperative guideline protocols while informing further research and strategies aimed to reduce opioid use and misuse and in predicting patient characteristics associated with increased opioid consumption after surgery

Introduction. The use of intraoperative liposomal bupivacaine (LB) peri-articular injection has been highly debated for total knee arthroplasty (TKA). We evaluated the effect of an institutional-wide discontinuation of intraoperative LB on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. Material and Methods. Between July 1, 2019 and November 30, 2019, an institutional policy discontinued use of intraoperative LB, while the volume of non-LB with epinephrine was increased from 40-ml to 60-ml. A historical cohort was derived from patients undergoing TKA between January 1, 2019 and June 30, 2019. All patients received the same opioid sparing protocol, minimizing variability in prescribing habits. No adductor canal blocks/pumps were utilized. Nursing documented verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Opiate administration events were derived as Morphine Milligram Equivalences (MMEs) per patient per 24-hour interval. To assess immediate postoperative functional status, the validated Activity Measure for Post-Acute Care (AM-PAC) tool was utilized. All time events were calculated relative to TKA completion instant. Results. 789 primary TKAs did not receive intraoperative LB, while 888 patients acted as controls. Age was significantly greater in patients that did not receive intraoperative liposomal bupivacaine (66.80±8.97 vs 65.57±9.46; p<.01). Gender, BMI, ASA physical status score, race, smoking status, marital status, surgical time, length of stay and discharge disposition were similar between the two groups (p>.05). Compared to historical controls, discontinuation of LB demonstrated no significant difference in postoperative inpatient VRS pain scores up to 72 hours (p>.05), opioid administration up to 96 hours (p>.05), or AM-PAC scores within the first 24 hours (p>.05). Discussion. Subjective pain scores, opioid consumption, and functional scores were unchanged in the early postoperative period following the discontinuation of intraoperative liposomal delivery of bupivacaine in TKA

Introduction. Postoperative pain is a concern for patients undergoing Total Knee Arthroplasty (TKA) and plays an important role in opioid consumption, length of stay, and postoperative function. The purpose of this study was to compare outcomes in patients who underwent primary TKA comparing femoral and sciatic (F+S) combination motor nerve block versus an adductor canal and the interspace between the popliteal artery and the capsule of the posterior knee (ACB+IPACK) combination sensory nerve block. Methods. 100 consecutive primary TKA cases performed by a single surgeon using the same surgical approach and implant design were reviewed. The first 50 patients received F+S nerve blocks and the second 50 received ACB+IPACK blocks preoperatively. Both groups also received total intravenous anesthesia (TIVA). Differences in opioid requirements, length of stay (LOS), distance walked, Western Ontario & McMasters University Osteoarthritis Index (WOMAC), Knee Society (KSS) function scores, Visual Analog Scores (VAS) for pain at rest and with activity, and postoperative complications were analyzed. There were no differences in the groups with respect to age, sex or BMI. Results. 62% of patients were discharged on postoperative day #1 in the ACB+IPACK group compared to 14% in the F+S group (p<.0001). The ACB+IPACK patients had a shorter LOS (average 1.48 days versus 2.02 days, p<0.0001), ambulated further on postop day #0 (average 21.4 feet versus 5.3 feet, p<0.0001), required less narcotics the day after surgery (average 15.7 versus 24.0 morphine equivalents p<0.0001) and at 2 weeks postoperative (average 6.2 versus 9.3 morphine equivalents, p=0.025), and required less manipulations under anesthesia (1 versus 5, p=0.204). WOMAC, KSS, and VAS scores were not significantly different. Discussion. The use of combination adductor canal and IPACK sensory blocks demonstrated improved early ambulation with decreased opioid use, length of stay, and postoperative manipulations. This study suggests that the use of combination sensory adductor canal and IPACK nerve blocks are superior to motor nerve blocks in patients undergoing primary TKA

Summary

Despite adoption of robust clinical pathways, narcotic administration within the inpatient setting is highly variable and may benefit from the implementation of standardized multi-modal pain management protocols.

Aims. Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. Methods. On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function. Results. A total of 888 patients received Protocol 1 and while 789 received Protocol 2. The mean age of the patients was significantly higher in those who did not receive LB (66.80 vs 65.57 years, p = 0.006). The sex, BMI, American Society of Anesthesiologists physical status score, race, smoking status, marital status, operating time, length of stay, and discharge disposition were similar in the two groups. Compared with the LB group, discontinuing LB showed no significant difference in postoperative VRS pain scores up to 72 hours (p > 0.05), opioid administration up to 96 hours (p > 0.05), or AM-PAC scores within the first 24 hours (p > 0.05). Conclusion. The control of pain after TKA with a multimodal management protocol is not improved by the addition of LB compared with traditional bupivacaine. Cite this article: Bone Joint J 2021;103-B(6 Supple A):102–107

Abstract. Introduction. To compare the efficacy of adductor canal blocks (ACB) and periarticular anesthetic injections (PAI) with bupivacaine in total knee arthroplasty. Methods. 90 patients undergoing primary total knee arthroplasty under spinal anesthesia were randomized to 1 of 3 groups: ACB alone (15 mL of 0.5% bupivacaine), PAI alone (50 mL of 0.25% bupivacaine with epinephrine) and ACB + PAI. Primary outcome in this study was the visual analog scale (VAS) pain score in the immediate postoperative period. Secondary outcomes included postoperative opioid use, activity level during physiotheraphy, length of hospital stay and ROM. Results. Mean VAS pain score was significantly higher with ACB alone, compared with the score after use of ACB+PAI, on POD1 and POD3. Total opioid consumption through POD3 was significantly higher when ACB alone had been used compared with PAI alone and ACB+PAI. Opioid consumption in the ACB-alone group was significantly higher than that in the ACB + PAI group on POD2 and POD3 and significantly higher than that in the PAI alone group on POD2. There was no significant difference in opioid consumption between the patients treated with PAI alone and those who received ACB + PAI. The activity level during physiotherapy on POD0 was significantly lower after use of ACB alone than after use of PAI alone or ACB + PAI. Conclusion. Higher pain scores after total knee arthroplasty done with an ACB and without PAI, suggesting that ACB alone is inferior for perioperative pain control. There were no significant differences between ACB alone, PAI alone and ACB + PAI inparameters measured

Introduction. Even as the outcomes of primary total knee arthroplasty (TKA) continue to improve, there remain increasing concerns about pain control after surgery and prolonged narcotic use. Cryoneurolysis has been demonstrated to reduce osteoarthritis knee pain for up to 90 days. We hypothesized that postoperative narcotic use could be reduced following preoperative cryoneurolysis of the superficial genicular nerves. Methods. Primary TKA patients were randomized into either a control or cryoneurolysis treatment group. Both followed the same preoperative, intraoperative, and postoperative pain management protocol, except the treatment group had cryoneurolysis of their superficial genicular nerves 3–7 days prior to surgery. All patients were prescribed 40 narcotic pills at discharge and pills were counted at 72 hours and at 2,6, and 12 weeks postoperatively. The primary endpoint was daily morphine equivalent (DME) based on pill count and secondary endpoints were changes in pain and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, Jr.) scores. Results. Per-protocol results demonstrated that the DME for the treatment group was significantly lower at 72 hours (10.9 mg vs. 14.9 mg, p=0.0389), 6 weeks (4.2 mg vs. 5.9 mg, p=0.0186) and 12 weeks (2.4 mg vs 3.4 mg p=0.0234). Overall, there was a 29% reduction in the DMEs over the entire 12-week postoperative period. Only 14% of the treatment group consumed opioids past 6 weeks compared to 44% of the control group (p=0.0005). The treatment group demonstrated a greater reduction in pain scores from baseline at 72 hours and 12 weeks. The treatment group also showed significant improvements in KOOS Jr. scores compared to the control group at all timepoints. Conclusions. The results demonstrate that preoperative cryoneurolysis can reduce opioid consumption after TKA. The early cessation of opioid consumption is especially encouraging given the association of prolonged narcotic use with increased complications following surgery. Preoperative cryoneurolysis should be considered as part of a multimodal protocol to reduce opioid consumption and pain and improve function after TKA. For figures, tables, or references, please contact authors directly

Introduction. The success of total knee arthroplasty (TKA) necessitates precise osteotomies and soft tissue balancing to realign the lower extremity to a neutral mechanical axis. While technological advances have facilitated precise osteotomies, soft tissue balancing has traditionally relied mostly on surgeons’ subjective and variable tactile feedback. As soft tissue imbalance accounts for 35% of early TKA revisions in North America, we aimed to compare outcomes when TKA was balanced free-hand versus a sensor-guided balancing device (VERASENSE, OrthoSensor, Inc (Dania, FL)). Methods. In a randomized-controlled fashion, patients underwent primary TKA soft tissue balancing either free-hand or with VERASENSE (Orthosensor Inc, Dania FL) at our institution beginning January 2018. With VERASENSE, soft-tissue balancing is considered when the pressure difference between the medial and lateral knee compartments was less than 15 pounds. Data regarding patient-reported outcomes, knee range of motion (ROM), pain level, opioid consumption, inpatient ambulation distance, length of stay (LOS), and incidence of arthrofibrosis was collected and analyzed in a two-year minimum follow-up and target patient goal of 120 patients. Results. The study cohort thus far consists of 53 patients, average age 72.4 ± 8.8 years. Soft-tissue balance was conducted freehand in 23 patients and the VERASENSE was used in 30 patients. In the free-hand cohort, preoperative patient-reported outcomes for SF-12 Physical, Mental, WOMAC (pain, stiffness, function) parameters, and knee society function score (KSFS) were 39.3, 45.8, 47.7, 37.5, 48.1, and 50.0, respectively and post-operative at 3 months were 45.0, 53.0, 79.5, 72.5, 81.0, and 72.5, respectively; difference between preoperative and post-operative ROM was +8.4 degrees; average VAS pain score in the first 3 post-operative days was 2.9 ± 2.3; average opioid consumption was 100.7 ± 103.3 mg morphine equivalents; average inpatient ambulation per day was 267.9 ± 187.4 feet; average LOS was 2.3 days. In the VERASENSE cohort, patient reported outcomes for SF-12 Physical, Mental, WOMAC (pain, stiffness, function) parameters, and knee society function score (KSFS) were 38.2, 48.6, 40.1, 30.3, 40.0, and 48.7, respectively and post-operative at 3 months were 41.9, 47.6, 67.2, 59.7, 69.1, and 56.7; difference between preoperative and post-operative ROM was +3.9 degrees; average VAS pain score in the first 3 post-operative days was 2.9 ± 2.3; average opioid consumption was 105.8 ± 86.7 mg morphine equivalents; average inpatient ambulation was 384.6 ± 316.1 feet; average LOS was 2.1 days. There was no incidence of arthrofibrosis and subsequent manipulation under anesthesia in the trial. Conclusion. Short-term follow up of this randomized-controlled trial demonstrates equivalent patient-reported and clinical outcomes when soft-tissue balancing in TKA is performed free-hand versus utilization of VERASENSE, though we hypothesize a difference in the long-term

Introduction. Controlling post-operative pain and reducing opioid requirements after total knee arthroplasty (TKA) remains a challenge, particularly in an era stressing rapid recovery protocols and early discharge. A single shot adductor canal block (ACB) has been shown to be effective in decreasing post-operative pain. This requires a specialty-trained Anesthesiologist skilled in ultrasound techniques, which imposes cost, time and skill barriers. Cadaveric studies and magnetic resonance imaging data have shown that access to the adductor canal is possible from within the joint, and thus the potential for intraoperative, intra-articular, surgeon administered ACB through a standard surgical approach is a feasible alternative to ultrasound guided ACB at the time of TKA. The purpose of the present study is to compare the efficacy of surgeon administered intraoperative ACB to anesthesiologist administered ACB. Methods. Patients' undergoing primary TKA were prospectively randomized to receive either an Anesthesiologist administered (Group 1) or Surgeon administered (Group 2) ACB using 15 ml of Ropivacaine 0.5%, both in conjunction with spinal anesthesia. Perioperative multimodal anesthesia was standardized for the two groups. Primary outcomes were pain visual analogue scale (VAS), range of motion, and opioid consumption. Secondary outcomes were patient satisfaction scores and length of stay (LOS). Results. 51 patients were enrolled and followed for a minimum of 6 weeks. 28 were randomized to Group 1 and 23 to Group 2. Opioid equivalents consumed were equal on POD 0,1, and 2 (p=0.86, 0.68, 0.47). Patients in Group 1 had significantly less pain on POD 0 [46.9 vs 61.8] (p=0.014), but there was no difference in pain on POD 1 or 2 (p=0.4, p=0.95). There was no difference in active flexion on post-operative day (POD) 0, POD 1 or 6 weeks post op (p=0.86, 0.074 and 0.59) and no difference in active extension on POD 0, 1, or 6 weeks (p=0.38,0.07and p=0.3). There was no difference in patient satisfaction with pain control on POD 0, 1, or 2 (p=0.6, p=0.7, p=0.9). There was no difference in LOS (1.3 vs 1.4 days p=0.34). Conclusion. Surgeon administered ACB is not inferior to Anesthesiologist administered ACB with respect to range of motion, patient satisfaction, or opioid consumption, although pain on the day of surgery may be greater. Surgeon administered ACB is an effective and cost- and time- efficient alternative to Anesthesiologist administered ACB. For figures, tables, or references, please contact authors directly

Introduction. Opioid abuse is a national epidemic. Traditional pain management after total knee arthroplasty (TKA) relied heavily on opioids. The evidence that in-hospital multimodal pain management (MMPM) is more effective than opioid-only analgesia is overwhelming. There has been little focus on post-discharge pain management. The purpose of this study was to determine whether MMPM after TKA could reduce opioid consumption in the 30-day period after hospital discharge. Methods. This was a prospective, two-arm, comparative study with a provider cross-over design. The first arm utilized a standard opioid-only (OO) prn regimen. The second arm utilized a 30-day MMPM regimen (standing doses of acetaminophen, metaxalone, meloxicam, gabapentin) and opioid medications prn. Surgeons crossed over protocols every four weeks. The primary outcome measure was VAS pain score. Secondary outcome measures included morphine milligram equivalents (MME) consumed, failure of the protocol, and manipulation under anesthesia (MUA). A pre-hoc power analysis was performed for the primary outcome measure and an intent-to-treat analysis was done utilizing a longitudinal mixed model. Results. There were 43 patients in the OO cohort and 39 patients in the MMPM cohort. There was no difference in the baseline demographics or preoperative scores (p=0.94). There was no clinically meaningful difference in VAS score between the two groups at any time. The average opioid consumption at 30-days was 469 and 344 MME's for the OO and MMPM cohorts, respectively (p=0.026). 19/43 (44.2%) patients in the OO cohort failed vs. 4/39 (10.3%) in the MMPM cohort (p=0.002). There was 1 MUA in the OO and none in the MMPM cohort (p=0.338). Discussion. A 30-day post-discharge multimodal pain regimen reduced opioid use after TKA. Opioid-only regimens are at an increased risk of failure to control pain. As a result of this study, multimodal pain management after hospital discharge is standard at our institution

Abstract. Introduction. This multi-centre randomised controlled trial evaluated the clinical and cost effectiveness of liposomal bupivacaine for pain and recovery following knee replacement. Methodology. 533patients undergoing primary knee replacement were randomised to receive either liposomal bupivacaine (266mg) plus bupivacaine hydrochloride (100mg) or control (bupivacaine hydrochloride 100mg), administered at the surgical site. The co-primary outcomes were pain visual analogue score (VAS) area under the curve (AUC) 6 to 72hours and the Quality of Recovery 40 (QoR-40) score at 72hours. Results. Primary analysis found no difference in pain VAS AUC 6 to 72hours between liposomal bupivacaine and control (MD -21.5 (97.5% CI -46.8 to 3.8; p=0.057)), nor the QoR-40 at 72hours (MD 0.54, 97.5% CI -2.05 to 3.13, p=0.643). Analyses of pain VAS and QoR-40 scores on days 0, 1, 2 and 3 demonstrated only one significant difference, with the liposomal bupivacaine arm having lower pain scores the evening of surgery (day0; MD -0.54, 97.5% CI -1.07 to -0.02; p=0.021). No difference in cumulative opioid consumption or functional outcome at 6weeks, 6months or 1year was detected. Heath economic analysis found liposomal bupivacaine to be less effective in terms of QALYs as well as more costly. No difference in adverse events between arms was identified. Conclusion. This is the largest RCT evaluating the clinical and cost effectiveness of liposomal bupivacaine It found that compared to bupivacaine hydrochloride local infiltration of liposomal bupivacaine at the surgical site does not provide any clinical or cost benefit for knee replacement and therefore should not be routinely used

The COVID-19 pandemic has led to unprecedented times worldwide. From lockdowns to masks now being part of our everyday routine, to the halting of elective surgeries, the virus has touched everyone and every part of our personal and professional lives. Perhaps, now more than ever, our ability to adapt, change and persevere is critical to our survival. This year's closed meeting of The Knee Society demonstrated exactly those characteristics. When it became evident that an in-person meeting would not be feasible, The Knee Society leadership, under the direction of President John Callaghan, MD and Program Chair Craig Della Valle, MD created a unique and engaging meeting held on September 10–12, 2020. Special recognition should be given to Olga Foley and Cynthia Garcia at The Knee Society for their flexibility and creativeness in putting together a world-class flawless virtual program. The Bone & Joint Journal is very pleased to partner with The Knee Society to once again publish the proceedings of the closed meeting of the Knee Society. The Knee Society is a United States based society of highly selected members who have shown leadership in education and research in knee surgery. It invites up to 15% international members; this includes some of the key opinion leaders in knee surgery from outside the USA. Each year, the top research papers from The Knee Society meeting will be published and made available to the wider orthopaedic community in The Bone & Joint Journal. The first such proceedings were published in BJJ in 2019. International dissemination should help to fulfil the mission and vision of the Knee Society of advancing the care of patients with knee disorders through leadership, education and research. The quality of dissemination that The Bone & Joint Journal provides should enhance the profile of this work and allow a larger body of surgeons, associated healthcare professionals and patients to benefit from the expertise of the members of The Knee Society. The meeting is one of the highlights of the annual academic calendar for knee surgeons. With nearly every member in attendance virtually throughout the 3 days, the top research papers from the membership were presented and discussed in a virtual format that allowed for lively interaction and discussion. There are 75 abstracts presented. More selective proceedings with full papers will be available after a robust peer review process in 2021, both online and in The Bone & Joint Journal. The meeting commenced with the first group of scientific papers focused on Periprosthetic Joint Infection. Dr Berry and colleagues from the Mayo Clinic further help to clarify the issue of serology and aspirate results to diagnose TKA PJI in the acute postoperative setting. 177 TKA's had an aspiration within 12 weeks and 22 were proven to have PJI. Their results demonstrated that acute PJI after TKA should be suspected within 6 weeks if CRP is ≥81 mg/L, synovial WBCs are ≥8500 cells/μL, and/or synovial neutrophils≥86%. Between 6– 12 weeks, concerning thresholds include a CRP ≥ 32 mg/L, synovial WBC ≥7450, and synovial neutrophils ≥ 84%. While historically the results of a DAIR procedure for PJI have been variable, Tom Fehring's study showed promise with the local delivery of vancomycin through the Intraosseous route improved early results. New member Simon Young contrasted the efficacy of the DAIR procedure when comparing early infections to late acute hematogenous PJI. DAIR failed in 63% of late hematogenous PJIs (implant age>1 year) compared to 36% of early (<1year) PJIs. Dr Masri demonstrated in a small group of patients that those with well-functioning articulating spacers can retain their spacers for over 12 months with no difference in infection from those that had a formal two stage exchange. The mental toll of PJI was demonstrated in a longitudinal study by Doug Dennis, where patient being treated with 2 stage exchange had 4x higher rates of depression compared to patient undergoing aseptic revision. The second session focused on both postoperative issues with regards to anticoagulation and manipulation. Steven Haas demonstrated high complication rates with utilization of anticoagulation for treatment of postoperative pulmonary embolism with modern therapeutic anticoagulation (warfarin, enoxaparin, Xa inhibitors) with the Xa inhibitors demonstrating lower complication rates. Two papers focused on the topic of manipulation. Mark Pagnano presented data on timing of manipulation under anesthesia up to even past 12 months. While gains were modest, a subset of patients did achieve substantial gains in ROM > 20degrees even after 3 months post op. Dr Westrich's study demonstrated no difference in MUA outcomes with either IV sedation or neuraxial anesthesia although the length of stay was shorter in the IV sedation group. Several studies in Session II focused on kinematics and femoral component position. Dr Li's in vivo kinematic study during weightbearing flexion and gait demonstrated that several knees rotated with a lateral pivot motion and not all knees can be described with a single motion character. Dr Mayman and his group utilized a computational knee model to demonstrate that additional distal femoral resection results in increasing levels of mid -flexion instability and cautioned against the use of additional bony resection as the first line for flexion contractures. Using computer navigation, Dr Huddleston's study nicely outlined the variability in femoral component rotation to achieve a rectangular flexion gap utilizing a gap balanced method. The third session opened the meeting on Friday morning. The focus was on unicompartmental knee arthroplasty and the increasing utilization of robotic assisted total knee arthroplasty. David Murray showed using registry data that for patient with higher comorbidities (ASA >3), UKA was safer and more cost effective than TKA while Dr Della Valle's group demonstrated overall lower average healthcare costs in UKA patients compared to TKA in the first 10 years after surgery. Dr Geller assessed UKA survivorship among 3 international registries. While survivorship varied by nation and designs, certain designs consistently had better overall performance. Dr Nunley and his group showed robotic navigation UKA significantly reduced outliers in alignment and overhang compared to manual UKA. Dr Catani's data demonstrated that full thickness cartilage loss should still be considered a requirement for UKA success even with robotic assistance. Despite a high dislocation rate of 4%, Mr Dodd demonstrated high survivorship for lateral UKA despite historical contraindications. The growing evidence for robotics TKA was demonstrated in two studies. Professor Haddad showed less soft tissue injury, reduced bone trauma and improved accuracy or rTKA compared to manual TKA while Dr Gustke single surgeon study showed his rTKA had improved forgotten joint scores and less ligament releasing required for balancing. Despite these finding, Dr Lee's study demonstrated that a robotic TKA could not guarantee excellent pain relief and other factors such a patient expectations and psychological factors play a role. Our fourth session was devoted to machine learning and smart tools and modeling. Dr Meneghini used machine learning algorithms to identify optimal alignment outcomes that correlated with patient outcomes. Several parameters such as native tibial slope, femoral sagittal position and coronal limb alignment correlated with outcomes. Along the same lines, Bozic and coauthors demonstrated that using AI algorithms incorporated with PROM's improved levels of shared decision making and patient satisfaction. Dr Lombardi demonstrated that a mobile patient engagement platform that provided smart phone-based exercise and education was comparable to traditional methods. Dr Mahfouz demonstrated the accuracy of using ultrasound to produce 3D models of the bone compared to conventional CT based strategies and Dr Mahoney showed the valued of a preop 3D model in reproducing more normal knee kinematics. The last two talks of the session focused on some of the positives of the COVID-19 pandemic, namely the embracing of telemedicine by patients and surgeons as demonstrated by Dr Slover and the increasing and far reaching educational opportunities made available to residents and fellows during the pandemic. Session five focused on risk stratification and optimization prior to TKA. Dr O'Connor demonstrated that that the implementation of an optimization program preoperatively reduced length of stay and ED visits, and Charles Nelson's study showed that risk stratification tool can lower complication rates in obese patients undergoing TKA comparable to those that are nonobese. Dr Markel's study demonstrated that those who have preoperative depression and anxiety are at higher risk of complications and readmissions after surgery and these issues should be addressed preoperatively. Interestingly, a study by Dr Callaghan demonstrated that care improvement pathways have not lowered the gap in complications for morbidly obese patients undergoing TKA, Dr Barsoum argued that the overall complication rates were low and this patient cohort had significant gains in PROMS after TKA that would not be experienced if arbitrary cutoff for limited surgery were established. The final session on Friday, Session six, had several well done and interesting studies. There continues to be mounting evidence that liposomal bupivacaine has little effect on managing post-operative pain to warrant its increased use. Bill Macaulay and colleagues showed no change in pain scores, opioid consumption and functional scores when liposomal bupivacaine was discontinued at a large academic medical center. Dr Bugbee importantly demonstrated that a supervised ambulation program reduced falls in the early postoperative period. Several paper on healthcare economics were presented. Rich Iorio showed that stratifying complexity of total joint cases between hospitals with a system can be efficient and cost savings while Dr Jiranek demonstrated in his study that complex TKAs can be identified preoperatively and are associated with prolonged operative time and cost of care and consideration should be given in future reimbursement models to a complexity modifier. Dr Springer, in their evaluation of Medicare bundled payment models, demonstrated that providers and hospitals in historical bundled models that became efficient were penalized in the new model, forcing many groups to drop out and return to a fee for service model. Ron Delanois important work showed that social determinants can have a major negative impact on outcomes following TKA. Our final day on Saturday opened with Session seven, and several interesting paper on metal ions/debris in TKA. Dr Whitesides simulator study showed the absence of scratches and material loss in a ceramic TKA compared with Co-Cr TKA and suggested an advantage to this material in patients with metal sensitivity. Conversely, in a histological study of failed TKA, perivascular lymphocytic infiltration was not associated with worse clinical outcomes or differences in revision in a series of 617 aseptic revisions, 19% of which had PVLI found on histology. The Mayo group and Dr Trousdale however, noted that serum metal ion levels can be helpful in identifying implant failure in a group of revision TKAs, especially those with metallic junctions. Dr Dalury demonstrated nicely that use of maximally conforming inserts did not have a negative effect on implant loosening in a series of 76 revision TKA's at an average follow up of 7 years, while Kevin Garvin and his group showed no difference in end of stem pain between cemented and cementless stems in revision TKA. The final two studies in the session by Bolognesi and Peters respectively showed that metaphyseal cones continue to demonstrate excelled survivorship in rTKA setting despite extensive bone loss. Session eight was highlighted by a large series of revision reported by new member Dr Schwarzkopf, who showed that revision TKA done by high volume surgeons demonstrated better outcomes and lower revision rates compared to surgeon who did less than 18 rTKA's per year. Dr Maniar importantly showed that preoperatively, patients with high activity level and low pain and indicated by a high preop forgotten joint score did poorly following TKA while David Ayers nicely demonstrated that KOOS scores that assess specific postoperative outcomes can predict patient dissatisfaction after TKA. The final paper in this session by Max Courtney showed that the majority of surgical cancellations are due to medical issues, yet a minority of these undergo any intervention specifically for that condition, but they resulted in a delay of 5 months. The first two studies of Session nine focused on polyethylene thickness. Dr Backstein demonstrated no difference in KSS scores, change in ROM and aseptic revision rates based on polyethylene thickness in a series of 195 TKA's. An interesting lab study by Dr Tim Wright showed a surprising consistency in liner thickness choice among varying levels of surgeon experience that did not correlate with applied forces or gap stability estimates. Two studies looked specifically at the issue of tibial loosening and implant design. Nam and colleagues were not able to demonstrate concerning findings for increasing tibial loosening in a tibial baseplate with a shortened tibial keel at short term follow up, while Lachiewicz demonstrated a 19% revision or revision pending rate in 223 cemented fixed bearing ATTUNE TKA at a mean of 30 months. Our final session of the meeting, began with encouraging news, that despite only currently capturing about 40% of TJA's done in the US, the American Joint Replacement Registry data is representative of data in other representative US databases. An interesting study presented by Robert Barrack looked at bone remodeling in the proximal tibia after cemented and cementless TKA of two different designs. No significant difference was noted among the groups with the exception of the cemented thicker cobalt chrome tray which demonstrated significantly more bone mineral density loss. Along the same lines, a study out of Dr Bostrom's lab demonstrated treatment of a murine tibial model with iPTH prevents fibrous tissue formation and enhances bone formation in cementless implants. New Member Jamie Howard showed no difference in implant migration and kinematics of a single radius cementless design using either a measured resection or gap balancing technique and Dr Cushner show no difference in blood loss with cemented or cementless TKA with the use of TKA. The final two studies looked at staging and bilateral TKA's. Peter Sharkey showed that simultaneous TKA's were associated with higher complication compared to staged TKA and that staged TKA with less than a 90-day interval was not associated with higher risk. However, Mark Figgie showed that patients undergoing simultaneous TKA compared to staged TKA, missed 17 fewer days of work. In spite of the virtual nature of the meeting, there were some outstanding scientific interactions and the material presented will continue to generate debate and to guide the direction of knee arthroplasty as we move forwards

Aims

Spinal anaesthesia has seen increased use in contemporary primary total knee arthroplasties (TKAs). However, controversy exists about the benefits of spinal in comparison to general anaesthesia in primary TKAs. This study aimed to investigate the pain control, length of stay (LOS), and complications associated with spinal versus general anaesthesia in primary TKAs from a single, high-volume academic centre.

Aims

Robotic-assisted total knee arthroplasty (RA-TKA) has been introduced to provide accurate bone cuts and help achieve the target knee alignment, along with symmetric gap balancing. The purpose of this study was to determine if any early clinical benefits could be realized following TKA using robotic-assisted technology.

Aims

Unicompartmental knee arthroplasty (UKA) provides improved early functional outcomes and less postoperative morbidity and pain compared with total knee arthroplasty (TKA). Opioid prescribing has increased in the last two decades, and recently states in the USA have developed online Prescription Drug Monitoring Programs to prevent overprescribing of controlled substances. This study evaluates differences in opioid requirements between patients undergoing TKA and UKA.

Aims

The purpose of this study was to use pharmacogenetics to determine the frequency of genetic variants in our total knee arthroplasty (TKA) patients that could affect postoperative pain medications. Pharmacogenetic testing evaluates patient DNA to determine if a drug is expected to have a normal clinical effect, heightened effect, or no effect at all on the patient. It also predicts whether patients are likely to experience side effects from medicine. We further sought to determine if changing the multimodal programme based on these results would improve pain control or reduce side effects.

Aims

Adductor canal block (ACB) has emerged as an alternative to femoral nerve block (FNB) for analgesia after total knee arthroplasty (TKA). The optimal duration of maintenance of the ACB is still questionable. The purpose of this study was to compare the analgesic benefits and physiotherapy (PT) outcomes of single-shot ACB to two different regimens of infusion of the continuous ACB, 24-hour and 48-hour infusion.

Controversy remains regarding the optimal post-operative analgesic regimen following total knee replacement. A delicate balance is required between the provision of adequate pain relief and early mobilisation. By reviewing 29 randomised trials we sought to establish whether local infiltration of analgesia directly into the knee during surgery provides better pain relief and a more rapid rehabilitation. Although we were able to conclude that local infiltration can provide improved post-operative pain relief, and to suggest the most promising technique of administration, there is no evidence that it reduces hospital stay.

Aims

Multimodal infiltration of local anaesthetic provides effective control of pain in patients undergoing total knee arthroplasty (TKA). There is little information about the added benefits of posterior capsular infiltration (PCI) using different combinations of local anaesthetic agents. Our aim was to investigate the effectiveness of the control of pain using multimodal infiltration with and without infiltration of the posterior capsule of the knee.