Should an Age Cutoff Be Considered for Elective Total Knee Arthroplasty Patients? An Analysis of Operative Success Based on Patient-Reported Outcomes.

Total knee arthroplasty (TKA) is increasing in the elderly population; however, some patients, family members, and surgeons raise age-related concerns over expected improvement and risks. This study aimed to (1) evaluate the relationship between age and change in patient-reported outcome measures (PROMs); (2) model how many patients would be denied improvements in PROMs if hypothetical age cutoffs were implemented; and (3) assess length of stay (LOS), readmission, reoperation, and mortality per age group. A prospective cohort of 4,396 primary TKAs (August 2015-August 2018) was analyzed. One-year PROMs were evaluated via Knee injury and Osteoarthritis Outcome Score (KOOS)-pain, -physical function short form (-PS), and -quality of life (-QOL), as well as Veterans Rand-12 (VR-12) physical (-PCS) and mental component (-MCS) scores. Positive predictive values (PPVs) of the number of postoperative "failures" (i.e., unattained minimal clinically important difference in PROMs) relative to number of hypothetically denied "successes" from a theoretical age-group restriction was estimated. KOOS-PS and QOL median score improvements were equivalent among all age groups (p = 0.946 and p = 0.467, respectively). KOOS-pain improvement was equivalent for ≥80 and 60-69-year groups (44.4 [27.8-55.6]). Median VR-12 PCS improvements diminished as age increased (15.9, 14.8, and 13.4 for the 60-69, 70-79, and ≥80 groups, respectively; p = 0.002) while improvement in VR-12 MCS was similar among age groups (p = 0.440). PPV for failure was highest in the ≥80 group, yet remained <34% for all KOOS measures. Overall mortality was highest in the ≥80 group (2.14%, n = 9). LOS >2, non-home discharge, and 90-day readmission were highest in the ≥80 group (8.11% [n = 24], p < 0.001; 33.7% [n = 109], p < 0.001; and 34.4% [n = 111], p = 0.001, respectively). Elderly patients exhibited similar improvement in PROMs to younger counterparts despite higher LOS, non-home discharge, and 90-day readmission. Therefore, special care pathways should be implemented for those age groups.

Similar Healthcare Utilization and 1-Year Patient-Reported Outcomes between Cemented and Cementless Primary Total Knee Arthroplasty: A Propensity Score-Matched Analysis.

Cementless fixation for total knee arthroplasty (TKA) has gained traction with the advent of newer fixation technologies. This study assessed (1) healthcare utilization (length of stay (LOS), nonhome discharge, 90-day readmission, and 1-year reoperation); (2) 1-year mortality; and (3) 1-year joint-specific and global health-related patient-reported outcome measures (PROMs) among patients who received cementless versus cemented TKA. Patients who underwent cementless and cemented TKA at a single institution (July 2015-August 2018) were prospectively enrolled. A total of 424 cementless and 5,274 cemented TKAs were included. The cementless cohort was propensity score-matched to a group cemented TKAs (1:3-cementless: n = 424; cemented: n = 1,272). Within the matched cohorts, 76.9% (n = 326) cementless and 75.9% (n = 966) cementless TKAs completed 1-year PROMs. Healthcare utilization measures, mortality and the median 1-year change in knee injury and osteoarthritis outcome score (KOOS)-pain, KOOS-physical function short form (PS), KOOS-knee related quality of life (KRQOL), Veteran Rand (VR)-12 mental composite (MCS), and physical composite (PCS) scores were compared. The minimal clinically important difference (MCID) for PROMs was calculated. Cementless TKA exhibited similar rates of median LOS (p = 0.109), nonhome discharge disposition (p = 0.056), all-cause 90-day readmission (p = 0.226), 1-year reoperation (p = 0.597), and 1-year mortality (p = 0.861) when compared with cemented TKA. There was no significant difference in the median 1-year improvement in KOOS-pain (p = 0.370), KOOS-PS (p = 0.417), KOOS-KRQOL (p = 0.101), VR-12-PCS (p = 0.269), and VR-12-MCS (p = 0.191) between the cementless and cemented TKA cohorts. Rates of attaining MCID were similar in both cohorts for assessed PROMs (p > 0.05, each) except KOOS-KRQOL (cementless: n = 313 (96.0%) vs. cemented: n = 895 [92.7%]; p = 0.036). Cementless TKA provides similar healthcare-utilization, mortality, and 1-year PROM improvement versus cemented TKA. Cementless fixation in TKA may provide value through higher MCID improvement in quality of life. Future episode-of-care cost-analyses and longer-term survivorship investigations are warranted.

Do patient-reported outcome measures improve after aseptic revision total hip arthroplasty?

BACKGROUND: The purpose of this study was to determine patient-reported outcome measures (PROMs) changes in: (1) pain, function and global health; and (2) predictors of PROMs in patients undergoing aseptic revision total hip arthroplasty (rTHA) using a multilevel model with patients nested within surgeon. METHODS: A prospective cohort of 216 patients with baseline and 1-year PROMs who underwent aseptic rTHA between January 2016 and December 2017 were analysed. The most common indication for rTHA was aseptic loosening, instability, and implant failure. The PROMs included in this study were HOOS Pain and HOOS Physical Function Short-form (PS), Veterans RAND-12 Physical Component Score (VR-12 PCS), and VR-12 Mental Component Score (MCS). Multivariable linear regression models were constructed for predicting 1-year PROMs. RESULTS: Mean 1-year PROMs improvement for aseptic revisions were 30.4 points for HOOS Pain and 22.1 points for HOOS PS. Predictors of better pain relief were patients with higher baseline pain scores. Predictors of better 1-year function were patients with higher baseline function and patients with a posterolateral hip surgical approach during revision. Although VR-12 PCS scores had an overall improvement, nearly 50% of patients saw no improvement or had worse physical component scores. Only 30.7% of patients reported improvements in VR-12 MCS. CONCLUSIONS: Overall, patients undergoing aseptic rTHA improved in pain and function PROMs at 1 year. Although global health assessment improved overall, nearly half of aseptic rTHA patients reported no change in physical/mental health status. The associations highlighted in this study can help guide the shared decision-making process by setting expectations before aseptic revision THA.

The Learning Curve of Reaching the Planned Limb Alignment in Robotic-Arm-Assisted Total Knee Arthroplasty.

Evidence on the learning curve associated with robotic-arm-assisted total knee arthroplasty (ra-TKA) is scarce and mostly based on operative time. Thus, the objective of this study was to assess a surgeon's learning experience based on accuracy to reach planned limb alignment and its impact on surgical-characteristics, limb-alignment, and perioperative-outcomes. A retrospective chart review was conducted on a consecutive series of 204 primary ra-TKAs (patients), performed by a single surgeon in a single institution (3/7/2018-to-6/18/2019). Cumulative summation control sequential analysis was used for the assessment of the learning curve using accuracy of reaching the planned limb alignment establishing that surgeries had an initial-learning-phase, followed by a second-consolidation-phase. Baseline demographics, operative/tourniquet times, prosthesis type, and limb alignment were compared between these two phases. Length of stay, discharge disposition, complications, reoperation/readmission (90 days), and total morphine equivalents (TMEs) prescribed were compared between phases. Independent sample t-tests, and chi-squared analyses were performed. ra-TKA demonstrated a learning curve of 110 cases for reaching planned limb alignment (p = 0.012). Robotic experience resulted in significantly more proportion of knees in neutral-axis postoperatively (p = 0.035) and significant reduction in TMEs prescribed (p = 0.04). The mean operative and tourniquet time were found to be significantly lower in second-phase versus the first-phase (p for both < 0.0001). ra-TKA has a significant learning curve in clinical practice. A surgeon can reach the planned limb alignment with increased accuracy over time (110-cases). Progressive robotic learning and associated operative time efficiency can lead to significantly lower opioid consumption in patients undergoing TKA.

No clinically meaningful difference in 1-year patient-reported outcomes among major approaches for primary total hip arthroplasty.

BACKGROUND: Debate continues around the most effective surgical approach for primary total hip arthroplasty (THA). This study's purpose was to compare 1-year patient-reported outcome measures (PROMs) of patients who underwent direct anterior (DA), transgluteal anterolateral (AL)/direct lateral (DL), and posterolateral (PL) approaches. METHODS: A prospective consecutive series of primary THA for osteoarthritis (n = 2390) were performed at 5 sites within a single institution with standardised care pathways (20 surgeons). Patients were categorised by approach: DA (n = 913; 38%), AL/DL (n = 505; 21%), or PL (n = 972; 41%). Primary outcomes were pain, function, and activity assessed by 1-year postoperative PROMs. Multivariable regression modeling was used to control for differences among the groups. Wald tests were performed to test the significance of select patient factors and simultaneous 95% confidence intervals were constructed. RESULTS: At 1-year postoperative, PROMs were successfully collected from 1842 (77.1%) patients. Approach was a statistically significant factor for 1-year HOOS pain (p = 0.002). Approach was not a significant factor for 1-year HOOS-PS (p = 0.16) or 1-year UCLA activity (p = 0.382). Pairwise comparisons showed no significant difference in 1-year HOOS pain scores between DA and PL approach (p > 0.05). AL/DL approach had lower (worse) pain scores than DA or PL approaches with differences in adjusted median score of 3.47 and 2.43, respectively (p < 0.05). CONCLUSIONS: Patients receiving the AL/DL approach had a small statistical difference in pain scores at 1 year, but no clinically meaningful differences in pain, activity, or function exist at 1-year postoperative.

A clinical review of robotic navigation in total knee arthroplasty: historical systems to modern design.

Robotic-assisted total knee arthroplasty (RA-TKA) has shown improved reproducibility and precision in mechanical alignment restoration, with improvement in early functional outcomes and 90-day episode of care cost savings compared to conventional TKA in some studies. However, its value is still to be determined.Current studies of RA-TKA systems are limited by short-term follow-up and significant heterogeneity of the available systems.In today's paradigm shift towards an increased emphasis on quality of care while curtailing costs, providing value-based care is the primary goal for healthcare systems and clinicians. As robotic technology continues to develop, longer-term studies evaluating implant survivorship and complications will determine whether the initial capital is offset by improved outcomes.Future studies will have to determine the value of RA-TKA based on longer-term survivorships, patient-reported outcome measures, functional outcomes, and patient satisfaction measures. Cite this article: EFORT Open Rev 2021;6:252-269. DOI: 10.1302/2058-5241.6.200071.

Florida State Opioid Prescription Restriction Law: Impact on Opioid Utilization After Total Joint Arthroplasty.

BACKGROUND: In response to the opioid epidemic, Florida recently passed the opioid prescription limiting law, effective since July 1st, 2018. However, its impact on opioid prescription after total joint arthroplasty (TJA) has not been elucidated. Thus, our objective was to assess if this new law led to reduced opioid prescription after TJA and to determine its impact on perioperative clinical outcomes. METHODS: A retrospective chart review was conducted on a consecutive series of 658 primary TJAs (618 patients), performed by four surgeons in a single institution [1/2/2018-10/23/2018]. Based on effective date of the law, cases were divided into: prelaw (327 cases; 168 hips/159 knees) and postlaw (331 cases; 191 hips/140 knees) phases. Baseline demographics and surgical characteristics were compared. The effect of the law on perioperative outcomes: length of stay, complications, emergency department/office visits, patient phone calls, reoperation or readmission (90 days), and total morphine equivalents prescribed was investigated. Independent sample t-tests and chi-square analyses were performed. RESULTS: Prelaw and postlaw phases had no significant difference in baseline demographics and characteristics. No difference was found in length of stay. Opioid law implementation led to significantly lower total oral morphine equivalents after TJAs [Prelaw: 1059.9 ± 825.4 vs postlaw: 942.8 ± 691.7; P = .04], but did not result in a significant increase in 90-day complications, patient visits (office or emergency) or phone calls, and reoperation or readmission. CONCLUSION: Our data suggest that Florida state opioid prescription limiting law has resulted in a marked decline in opioid prescription without any increase in rates of patient visits, phone calls, or readmission after TJA.

Results of preoperative screening for COVID-19 correlate with the incidence of infection in the general population -a tertiary care experience.

Objectives: Many hospitals have recently instituted policies mandating preoperative COVID-19 testing. However, it is uncertain whether institutions can dictate such policies based on infection rates found in the general population. Therefore, the main aims of the study were to determine (1) what proportion of preoperative patients tested positive, (2) what percentage was asymptomatic, and (3) whether variations throughout time in numbers of positive patients reflected changes observed in our state.Methods: All COVID-19 preoperative screening tests (nasopharyngeal-swab RT-PCR testing) performed in our hospital between 04/13/2020 and 08/27/2020 were retrospectively reviewed. The unit of analysis was number of patients who tested negative/positive. Medical records of positive patients were reviewed to determine the presence of COVID-19 symptoms. A curve was created showing our number of positive patients per week and another one presenting the number of positive patients per day in Florida, both figures were compared.Results: A total of 7,213 patients from all specialties were preoperatively tested, out of which 85 were positive for an overall infection rate of 1.2%. In 18% (15/85) of positive patients, it was not possible to determine symptomatology. Among remaining patients, 49% (34/70) were asymptomatic while 51% (36/70) were symptomatic for COVID-19. Peak of positive cases occurred in mid-July in both curves, and the upward and downward tendencies in positive numbers mirrored each other.Conclusion: COVID-19 infection rate among our preoperative patients was very low. Nearly 50% of positive patients were asymptomatic. Our data suggest that a tertiary hospital can promulgate COVID-19 preoperative screening policies based on infection trends observed in the general population. However, in addition to the test, patients should be encouraged to self-quarantine for 14 days before surgery.

The Potential Effects of Imposing a Body Mass Index Threshold on Patient-Reported Outcomes After Total Knee Arthroplasty.

BACKGROUND: Operative eligibility thresholds based on body mass index (BMI) alone may risk restricting access to improved pain control, function, and quality of life. This study evaluated the use of BMI-cutoffs to offering TKA in avoiding: 1) 90-day readmission, 2) one-year mortality, and 3) failure to achieve clinically important one-year PROMS improvement (MCID). METHODS: A total of 4126 primary elective unilateral TKA patients from 2015 to 2018 were prospectively collected. For specific BMI(kg/m2) cutoffs: 30, 35, 40, 45, and 50, the positive predictive value (PPV) for 90-day readmission, one-year mortality, and failure to achieve one-year MCID were calculated. The number of patients denied complication-free postoperative courses per averted adverse outcome/failed improvement was estimated. RESULTS: Rates of 90-day readmission and one-year mortality were similar across BMI categories (P > .05, each). PPVs for preventing 90-day readmission and one-year mortality were low across all models of BMI cutoffs. The highest PPV for 90-day readmission and one-year mortality was detected at cutoffs of 45 (6.4%) and 40 (0.87%), respectively. BMI cutoff of 40 would deny 18 patients 90-day readmission-free, and 194 patients one-year mortality-free postoperative courses for each averted 90-day readmission/one-year mortality. Such cutoff would also deny 11 patients an MCID per avoided failure. Implementing BMI thresholds alone did not influence the rate of improvements in KOOS-PS, KRQOL, or VR-12. CONCLUSION: Utilizing BMI cutoffs as the sole determinants of TKA ineligibility may deny patients complication-free postoperative courses and clinically important improvements. Shared decision-making supported by predictive tools may aid in balancing the potential benefit TKA offers to obese patients with the potentially increased complication risk and cost of care provision.

Does the Timing of the Second Surgery of a Staged Bilateral Total Joint Arthroplasty Affect the Rate of Hospital Adverse Events and Perioperative Outcomes?

BACKGROUND: The optimal timing of the second surgery in primary staged bilateral total hip/knee arthroplasty remains uncertain. Perioperative hospital adverse events represent a significant issue, even "minor events" lead to substantial costs in workup tests, interconsultations, and/or increased hospital length-of-stay (LOS). Therefore, we sought to ascertain whether the timing of the second arthroplasty affects perioperative outcomes and/or rates of adverse events. METHODS: We retrospectively reviewed a consecutive series of 670 primary staged bilateral total hip/knee arthroplasty performed by 2 surgeons (2010-2016) at a single institution. The days between both arthroplasties were calculated for each pair of hips or knees. We evaluated demographics and LOS, discharge disposition, adverse events (ie, nausea, pulmonary embolism), and transfusion rates. The second arthroplasties (n = 335) were set apart in 2 groups based on the time they were done with respect to their corresponding contralateral first arthroplasty using 3 different thresholds: (1) ≤90 vs >90 days, (2) ≤180 vs >180 days, and (3) ≤365 vs >365 days. RESULTS: No significant differences in outcome comparisons were observed using either 90 or 180 days thresholds. However, using the 365 days thresholds, the mean LOS (2.21 vs 1.92 days, P = .015), adverse event (26% vs 15.3%, P = .021), total transfusion (7.4% vs 1.5%, P = .020), and allogeneic transfusion (6.9% vs 1.5%, P = .033) rates were significantly higher in second arthroplasties performed at or less than 1 year apart from the first, respectively. CONCLUSION: Staging the second arthroplasty more than a year apart from the first one seems to offer better LOS and rates of hospital adverse events, transfusions. However, unless patients are willing to wait a year between surgeries, our data also suggest no increased risk in regards to adverse events when proceeding before or after 90/180 days. LEVEL OF EVIDENCE: Level III.

The Utility of Serum d-Dimer for the Diagnosis of Periprosthetic Joint Infection in Revision Total Hip and Knee Arthroplasty.

BACKGROUND: There is scarce and contradicting evidence supporting the use of serum d-dimer for the diagnosis of periprosthetic joint infection in revision total hip (THA) and knee (TKA) arthroplasty. Therefore, the purpose of this study is to test the accuracy of serum d-dimer against the 2013 International Consensus Meeting (ICM) criteria. METHODS: A retrospective review was performed on a consecutive series of 172 revision THA/TKA surgeries performed by 3 fellowship-trained surgeons at a single institution (August 2017 to May 2019) and that had d-dimer performed during their preoperative workup. Of this cohort, 111 (42 THAs/69 TKAs) cases had complete 2013 ICM criteria tests and were included in the final analysis. Septic and aseptic revisions were categorized per 2013 ICM criteria ("gold standard") and compared against serum d-dimer using an established threshold (850 ng/mL). Sensitivity, specificity, likelihood ratios, and positive/negative predictive values were determined. Independent t-tests, Fisher's exact tests, chi-squared tests, and receiver operating characteristic curve analysis were performed. RESULTS: There was no statistically significant difference in baseline demographics between septic and aseptic cases per 2013 ICM criteria. When compared to ICM criteria, d-dimer demonstrated high sensitivity (95.9%) and negative predictive value (90.9%) but low specificity (32.3%), positive predictive value (52.8%), and overall, poor accuracy (61%) to diagnose periprosthetic joint infection. Positive likelihood ratio was 1.42 while negative likelihood ratio was 0.13. The area under the curve (AUC) was 0.742. CONCLUSION: Serum d-dimer has poor accuracy to discriminate between septic and aseptic cases using a described threshold in the setting of revision THA and TKA.

Dual Antibiotic Prophylaxis in Total Knee Arthroplasty: Where Do We Stand?

The risk of surgical site infection in primary total knee arthroplasty (TKA) has been reduced with the use of prophylactic antibiotics. First or second generation cephalosporins are still recommended as the primary prophylactic choice, but with the rise in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, evidence has emerged in favor of using dual antibiotics including vancomycin. However, it is unclear whether these combinations of antibiotic regimens further reduce postoperative infection rates. As a result, the objective of this review is to summarize the current literature concerning the use of dual prophylactic antibiotics in TKA. The most common dual prophylactic antibiotic combination is cefazolin (C) and vancomycin (V). In general, when comparing the effectiveness of single versus dual antibiotics, conflicting results have been reported. Three studies demonstrated no substantial decrease in overall postoperative infection rates with the use of dual antibiotics when compared with cefazolin alone. One found a significant decrease only in MRSA infection rates when using cefazolin and vancomycin (CV) (0.8% C alone vs. 0.08% CV, p < 0.05). Another investigation evaluated revision TKA patients who had combined cefazolin and vancomycin prophylaxis and showed a significant decline in both overall infection (7.89% [C] vs. 3.13% [CV]) and MRSA infection rates (4.21% [C] vs. 0.89% [CV]; p < 0.05). Concerning the safety profile of dual antibiotics, particular precautions must be adopted with the use of vancomycin because of the risk of acute kidney injury. Instead of vancomycin, an alternate less nephrotoxic antibiotic option might be teicoplanin. Unfortunately, this latter agent is only available outside of the United States. In conclusion, the value of dual antibiotic prophylaxis for the prevention of periprosthetic knee infections remains unclear primarily because all comparative studies performed between dual and single antibiotics have been of low evidence with retrospective designs. Larger multicenter randomized controlled trials are warranted.

Hospital Adverse Events and Perioperative Outcomes in Bilateral Direct Anterior Approach Total Hip Arthroplasty.

BACKGROUND: Perioperative hospital adverse events represent a significant outcome that is often overlooked. Even "minor events" such as fever or tachycardia may lead to significant costs due to workup tests, interconsultations, and/or increased length of stay (LOS). The optimal timing of bilateral direct anterior approach total hip arthroplasty (DAA-THA) remains unsettled. Consequently, we wanted to compare hospital LOS, discharge disposition, hospital adverse events (major and minor), and transfusion rates between simultaneous and staged bilateral DAA-THA. METHODS: A retrospective chart review was conducted on a consecutive series of 347 primary bilateral DAA-THAs (204 patients) performed by 2 surgeons in a single institution (2010-2016). The hips finally included were categorized as simultaneous (Sim-n = 61), staged 1 (Stg1-n = 143), or staged 2 (Stg2-n = 143). We also compared simultaneous with staged surgeries performed ≤1 and >1 year apart. Baseline demographics, LOS, discharge disposition, hospital adverse events, and transfusions were assessed. RESULTS: The simultaneous group had significantly younger patients and a higher proportion of males when compared with the staged groups and showed significant longer LOS [2.61 (Sim) vs 2.06 (Stg1) vs 1.63 (Stg2) days, P < .001], lower proportion of home discharge [77% (Sim) vs 91.6% (Stg1) vs 96.5% (Stg2), P < .001], as well as higher (overall) rate of adverse events [31.1% (Sim) vs 28.7% (Stg1) vs 14.0% (Stg2), P = .003] and transfusions [45.9% (Sim) vs 6.3% (Stg1) vs 7.0% (Stg2), P < .001]. However, most transfusions were autologous [37.7% (Sim) vs 3.5% (Stg1) vs 0% (Stg2), P < .001]. CONCLUSION: Our data show that bilateral DAA-THAs performed in a staged fashion, rather than simultaneously, have a shorter hospital LOS and decreased rates of adverse events and overall transfusions. Notwithstanding, simultaneous surgery should still be considered an option in selected patients. LEVEL OF EVIDENCE: Level III.

Serum D-Dimer in the Diagnosis of Periprosthetic Knee Infection: Where Are We Today?

Periprosthetic joint infection (PJI) continues to impact a remarkable number of patients who undergo total knee arthroplasty (2.0-2.1%). Substantial efforts to curtail these rates have been seen in the past decade including various attempts to reach a clear definition of PJI that the orthopaedic community could adopt as a gold standard. The Musculoskeletal Infection Society (MSIS) criteria, slightly modified by the International Consensus Meeting (ICM), has gained widespread acceptance and it is a step closer to that goal. Research on markers such as serum cross-linked D-fragments (D-dimer) seems promising in the diagnosis of infection. In the setting of PJI, a recent publication has established a threshold of 850 ng/mL as the optimal cutoff value for serum D-dimer. Therefore, our objective is to present a summary of the current literature on the changing indications of D-dimer and its rising importance in the setting of PJI. Serum D-dimer has been shown to outperform other conventional tests such as erythrocyte sedimentation rate and C-reactive protein that have been a major part of the ICM criteria and it has been included in the newly proposed diagnostic criteria for PJI that correctly diagnoses infection in 95.5% of septic patients (overall sensitivity: 97.7%, specificity: 99.5%). In comparison with the ICM and MSIS infection definitions, the new criteria revealed a higher sensitivity (97.7 vs. 86.9% and 97.7 vs. 79.3%, respectively), while specificity was similar. In conclusion, high D-dimer levels in primary or revision knee arthroplasty seem indicative of diagnosis of PJI. However, future studies are warranted to conclusively support the routine use of this marker and to validate the performance of the newly developed PJI diagnostic criteria under different clinical scenarios.

Histoplasma capsulatum periprosthetic knee infection complicated by autoimmune-mediated systemic inflammatory response syndrome.

Histoplasma capsulatum periprosthetic knee infection has rarely been reported in the literature due to its low frequency. Notwithstanding, it is important to keep it among the differential diagnoses to avoid delays in treatment. The current report presents the case of infectious knee monoarthritis in an immunocompetent patient after unicompartmental knee arthroplasty. The joint infection was accompanied by disseminated histoplasmosis, which initiated an autoimmune reaction, ensuing a systemic inflammatory response syndrome. The management protocol used in this case was successful and included staged arthroplasty reconstruction combined with chronic antifungal and steroid pharmacotherapy. Approximately 4 years after total knee arthroplasty revision, there were no clinical signs of localized or systemic infection.

The trends in robotic-assisted knee arthroplasty: A statewide database study.

OBJECTIVE: Recent technological advancements have led to the utilization of robotic-assisted knee arthroplasty (raKA) in the operating room. METHODS: All patients who underwent knee arthroplasty from 2009 to 2013 in NYS SPARCS were reviewed. raKAs and non-raKAs were compared for utilization and institutional trends. RESULTS: Robotic-assistance increased by 500%. 80% of raKAs were performed in teaching hospitals. The trend increase was greater in teaching hospitals. Blood transfusion rates differed between raKA and non-raKA (6.6% vs. 10.9%, p < 0.001). CONCLUSION: raKA utilization increased in NYS, moreso within teaching hospitals. raKA transfusion rates were lower but higher in teaching hospitals, potentially related to learning curve.

Are Patients More Satisfied With a Balanced Total Knee Arthroplasty?

BACKGROUND: Patient-reported outcome measures are increasingly recognized as an important tool in quantifying the clinical success of arthroplasty surgery. The aim of this study is to measure post-operative joint awareness and satisfaction in patients with and without a quantitatively balanced knee following primary total knee arthroplasty (TKA). METHODS: In this multi-center study, a total of 318 eligible patients were assigned to one of the 2 patient groups: sensor-guided TKA or surgeon-guided TKA. In the sensor-guided group, quantitative balancing was performed according to intercompartmental tibiofemoral load measurements measured by an instrumented tibial trial component. In contrast, for the surgeon-guided group, the knees were balanced according to the surgeons' standard manual techniques while blinding the surgeon to the sensor measurements. Patients were blinded to their allocation and filled out the validated Forgotten Joint Score and 2011 Knee Society Satisfaction questionnaires at 6 weeks and 6 months. For the purposes of this study, the subjects were pooled and stratified by their state of soft tissue balance, based on the mediolateral load differential through the range of motion. RESULTS: In the surgeon-guided group, approximately 50% of the cases yielded a quantitatively balanced knee. Significantly more balanced knees were observed in the sensor-guided group (84.0%). More importantly, for both outcome measures, the balanced group of patients reported significantly better outcomes scores. CONCLUSION: This demonstrates that using sensor feedback during knee arthroplasty surgery results in a more reproducible procedure, resulting in a higher percentage of balanced patients who in turn demonstrate superior clinical outcomes compared to unbalanced patients.

Positive Alpha-defensin at Reimplantation of a Two-stage Revision Arthroplasty Is Not Associated with Infection at 1 Year.

BACKGROUND: Diagnosing periprosthetic joint infection (PJI) represents a challenge that relies on multiple clinical and laboratory criteria that may not be consistently present. The synovial alpha-defensin-1 (AD-1) test has been shown to correlate accurately with the Musculoskeletal Infection Society (MSIS) criteria for the diagnosis of PJI, however, its association with persistent PJI has not been elucidated in the setting of patients receiving antibiotic spacers during second-stage reimplantation. Applying a Delphi-based consensus to define successful eradication of PJI offers an opportunity to test the utility of AD-1 in this setting. QUESTIONS/PURPOSES: (1) Can the AD-1 test determine whether infection has been controlled using the Delphi criteria for persistent PJI as a surrogate for infection eradication during two-stage revision for PJI treatment with a spacer? (2) How does the performance of the AD-1 test compare with the MSIS criteria? METHODS: This was a multicenter analysis of retrospectively collected data on patients who underwent a two-stage revision arthroplasty between May 2014 and July 2016. We included patients who had a previously confirmed PJI and received a cement spacer, underwent the second stage, had MSIS criteria data and a synovial fluid AD-1 test, and had a minimum followup of 1 year. We were unable to determine for all study sites how many patients had the test but did not meet all the criteria and so could not be studied; however, we were able to identify 69 patients (43 knees, 26 hips) who met all criteria. During the period in question, indications for use of AD-1 varied by surgeon; however, during that time, in general if a surgeon ordered it as part of the initial workup, the test would have been repeated before the second-stage reimplantation procedure. To assess the validity of AD-1 against persistence of PJI criteria at 1 year, the following were calculated using the Delphi criteria for persistent PJI as the gold standard: sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve (AUC) with 95% confidence intervals (CIs). Concordance index (c-index) and its Wald 95% CI with receiver operating characteristic (ROC) curve were calculated in relation to Delphi criteria for persistent PJI using AD-1 and then MSIS criteria. The two c-indices of AD-1 and MSIS were compared using the DeLong nonparametric approach. RESULTS: The AD-1 test showed poor sensitivity (7%; 95% CI, 0.2-34), and poor overall accuracy (73%; 95% CI, 60-83; AUC = 0.5; 95% CI, 0.3-0.6) in detecting infection eradication at 1 year. The c-index for AD-1 versus Delphi criteria for persistent PJI was 0.519 (95% CI, 0.44-0.60), and the c-index for MSIS criteria versus Delphi criteria for persistent PJI was 0.518 (95% CI, 0.49-0.54), suggesting the weak diagnostic abilities of these models. The contrast estimate between MSIS criteria and AD-1 were not different from one another at -0.001 (95% CI%, -0.09 to 0.09; p = 0.99). CONCLUSIONS: We found that a positive synovial fluid AD-1 test correlated poorly with the presence of persistent infection 1 year after two-stage revision arthroplasty for PJI. For this reason, we recommend against the routine use of AD-1 in patients with cement spacers, until or unless future studies demonstrate that the test is more effective than we found it to be. LEVEL OF EVIDENCE: Level IV, diagnostic study.

Antibiotic cement spacer for isolated medial wall acetabular deficiency in the setting of infected hip arthroplasty.

Periprosthetic joint infections remain challenging for orthopaedic surgeons. These are typically treated with 2-stage revision with an antibiotic spacer and arthroplasty reimplantation after infection eradication. We report a novel technique to create an antibiotic cement spacer construct in the setting of significant acetabular medial wall destruction due to osteolysis and infection. The medial wall of the acetabulum was reconstructed using antibiotic cement with 2 screws acting as a rebar. An acetabular liner was then cemented into place forming a cement construct similar to a reconstruction cage in function. This technique created a firm acetabular construct that allowed for the placement of a stable articulating spacer. The spacer allowed for infection eradication and was successfully converted into a revision total hip arthroplasty.