Efficacy and Safety of Catheter Interventions for Postoperative Urinary Retention After Primary Hip and Knee Total Joint Arthroplasty.

INTRODUCTION: Postoperative urinary retention (POUR) is a common barrier to rapid-discharge hip and knee total joint arthroplasty (TJA). We evaluated the efficacy and safety of catheterization intervention methods for POUR before and after discharge. METHODS: A total of 1,659 primary TJAs were retrospectively reviewed. POUR resolutions before and after discharge were evaluated relative to catheterization type and other covariates. Complications before and within 90 days of discharge were quantified. A total of 113 POUR cases comprised the analysis sample of 76 hips and 37 knees in 51 women and 62 men with an average age and body mass index of 68.6 (range 22 to 92) years and 31.7 (range 16 to 49) kg/m2. RESULTS: POUR resolved before discharge for 82.3% (93/113) of patients, with equivalent resolution rates for intermittent catheterization alone (84.2%, 32/38) compared with indwelling catheterization with or without intermittent catheterization (82.6%, 57/69, P < 0.999), equivalent time to resolution (P = 0.319), and no difference in complication rates (P = 0.999). Complication rates within 90 days of discharge were higher for patients treated with indwelling catheters before discharge (P = 0.049). Resolution before discharge was more likely with increasing body mass index (P = 0.026) and less likely for patients with a history of urinary retention (P = 0.033). 60 percent (12/20) of patients with unresolved POUR were discharged with self-intermittent catheterization and 40% (8/20) with indwelling catheters, with no differences in efficacy and safety based on the catheterization type (P = 0.109). DISCUSSION: Before discharge, we observed equivalent resolution rates and equivalent time to resolution for indwelling and intermittent catheterization alone without compromising patient safety. Intermittent catheterization is favored, however, because in situ catheter exposure is dramatically reduced and postdischarge complication rates are lower. Additional research is needed to develop evidence-based POUR guidelines for outpatient TJA.

Comparison of Delphi Consensus Criteria and Musculoskeletal Infection Society Outcome Reporting Tool Definitions of Successful Surgical Treatment of Periprosthetic Knee Infection.

BACKGROUND: Agreement on success following surgical treatment for periprosthetic joint infection (PJI) is important for comparing the efficacy of different surgical approaches with varying consequences and outcomes and setting patient expectations. We compared success rates following two-stage exchange arthroplasty for knee PJI using two expert-consensus definitions of success. METHODS: Prospectively documented data for 57 knees treated by a single surgeon at an academic tertiary care center were retrospectively reviewed. Treatment outcomes were quantified using the Delphi Consensus Criteria and the Musculoskeletal Infection Society Outcome Reporting Tool (MSIS ORT). RESULTS: Success rates were 81% using the Delphi Consensus Criteria and 56% using the MSIS ORT (P = .008). The MSIS ORT success rates increased to 76% when aseptic revisions and deaths unrelated to PJI were not penalized as failures of treatment. Predicted probabilities of successful treatment in a hypothetical case scenario were lowest based on the MSIS ORT and similarly higher using Delphi Consensus Criteria and MSIS ORT modified for both women (53.0, 90.8, and 88.7%) and men (29.1, 89.1, and 89.3%). CONCLUSIONS: Study observations underscore the need for a uniformly accepted single definition of surgical treatment success.

Infection Rates After Aseptic Revision Total Hip Arthroplasty With Extended Oral Antibiotic Prophylaxis.

INTRODUCTION: Few US studies have investigated the efficacy of extended oral antibiotic prophylaxis (EOAP) in the prevention of periprosthetic joint infection (PJI) after aseptic revision total hip arthroplasty (R-THA). This study compared PJI rates in aseptic R-THA performed with EOAP with PJI rates in published studies of aseptic R-THA patients not receiving EOAP. METHODS: Prospectively documented data on 127 consecutive aseptic R-THAs were retrospectively reviewed. Evidence-based perioperative infection prevention protocols were used, and all patients were discharged on 7-day EOAP. Superficial and deep infections at 30 and 90 days postoperatively and at mean latest follow-up of 27.8 months were statistically compared with all US studies reporting the prevalence of PJI after aseptic R-THA. Complications related to EOAP within 120 days of the index procedure also are reported. RESULTS: No superficial or deep infections were observed at 30 and 90 days postoperatively when 7-day postdischarge EOAP was used. Superficial and deep infection rates were 1.57% (two patients) and 3.15% (four patients) at mean latest follow-up, respectively. Comparisons with published 30-day PJI rates of 1.37% ( P = 0.423) and 1.85% ( P = 0.257) were not statistically significant. Two of four comparisons with published 90-day PJI rates of 3.43% ( P = 0.027) and 5.74% ( P = 0.001) were statistically different. The deep PJI rate of 3.15% at mean latest follow-up was significantly lower than two of three published rates at equivalent follow-up including 10.10% ( P = 0.009) and 9.12% ( P = 0.041). No antibiotic-related complications were observed within 120 days of the index procedure. DISCUSSION: Study findings possibly support the use of EOAP after aseptic R-THA to prevent catastrophic PJI with revision implants, indicating that the efficacy of EOAP cannot be definitively ruled-in or ruled-out based on available evidence.

Implant Position, Survivorship, and Patient-Reported Outcomes in Manual Medial Unicompartmental Knee Arthroplasty.

BACKGROUND: Two related recent reports described high error rates for implant positioning and reduced implant survivorship in manual unicompartmental knee arthroplasty (MUKA) compared to robotic-assisted unicompartmental knee arthroplasty (RUKA). The present study scientifically replicated these reports by comparing MUKAs similarly performed by an experienced high-volume surgeon in similar patients using the same study methods as these reports. METHODS: A total of 216 consecutive MUKAs were retrospectively evaluated radiographically for achievement of implant positioning targets. Achievement of targets was compared to the published MUKA and RUKA outcomes and correlated with revision rates and patient-reported outcome measures. RESULTS: There were 20% of study MUKAs compared to 88.1% of comparison MUKAs (P < .001) and 31.4% of comparison RUKAs (P < .048) that failed to meet all 7 implant positioning targets. The MUKA revision rates were significantly lower in the study sample than for comparison MUKAs (3.2% versus 14.2%, P < .001). Implant survivorship was 91.7% (95% confidence interval 84.9, 98.5%) at 8.9 years compared to 70.0% (95% confidence interval 56.0, 80.0%) at 10.2 years, respectively. Most patient-reported outcome measures did not differ based on achievement of implant positioning targets (P ≥ .072). CONCLUSIONS: Present study findings indicate that observations in the 2 recent reports may not be generalizable to all UKA surgeons. Additional data on the relationship between implant positioning and revision as well as functional outcomes are needed to identify appropriate robotic arthroplasty applications.

Predictors of Failure to Achieve Planned Same-Day Discharge after Primary Total Joint Arthroplasty: a Multivariable Analysis of Perioperative Risk Factors.

INTRODUCTION: Failure to achieve planned same-day discharge (SDD) primary total joint arthroplasty (TJA) occurs in as many as 7% to 49% of patients in the United States. This study evaluated the association between 43 perioperative risk factors and SDD failure rates. METHODS: A retrospective analysis of prospectively collected data from 466 primary TJAs with planned SDD to home was performed. Surgeries were performed at an academic tertiary care center comprising a hospital facility and a stand-alone ambulatory surgery center (ASC) on the same campus. Factors associated with failed SDD were identified using a multivariable analysis. RESULTS: Only one of 316 (0.3%) patients who underwent surgery in the ASC failed planned SDD ( P < 0.001) compared with 33.3% of 150 patients who underwent surgery in the hospital. The ASC failure was because of pain that interfered with physical therapy. Sixty-two percent (n = 31) of hospital failures were attributed to medical complications, 24% (n = 12) to physical therapy clearance, 8% (n = 4) to not being seen by internal medicine or therapy on the day of surgery, and 6% (n = 3) to unknown causes. Failure was increased in patients with preoperative anemia ( P = 0.003), nonwhite patients ( P = 0.002), patients taking depression/anxiety medication ( P = 0.015), and for every 10-morphine milligram equivalent increase in opioids consumed per hour in the postacute care unit ( P = 0.030). DISCUSSION: Risk stratification methods used to allocate patients to ASC versus hospital outpatient TJA surgery predicted SDD success. Most failures were secondary to medical causes. The findings of this study may be used to improve perioperative protocols enabling the safe planning and selection of patients for SDD pathways.

Time Required for Planned and Unplanned Episodes of Care in Aseptic Hip and Knee Revision Arthroplasty.

BACKGROUND: Studies indicate aseptic revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) requires much more effort but is reimbursed less than primary procedures per minute work time. This study quantified planned and unplanned work performed by the surgeon and/or their team during the entire episode of care "reimbursement window" and compared it to allowed reimbursement times by Centers for Medicare and Medicaid Services (CMS). METHODS: Between October, 2010, and December, 2020, all unilateral aseptic rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated from surgery scheduling to 90 days postoperative. Impromptu patient inquiries and treatments after discharge but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient. Work time was compared to CMS allowable times for rTHA (617 minutes) and rTKA (520 minutes). RESULTS: There were 292 Aseptic rTKA and 63 aseptic rTHA procedures included. Based upon CMS allowable times per patient there were a mean of 4.4 hours (267 minutes) of uncompensated care time per rTKA patient and a mean of 2.4 hours (141 minutes) of uncompensated care time per rTHA patient. CONCLUSION: Aseptic revisions are substantially more complex than primaries, requiring work effort that is not commensurate with current reimbursements. Financially disincentivizing surgeons to care for patients requiring revision surgery could reduce patient access to care when high quality care is needed the most.

Same-Day Discharge Following Aseptic Revision and Conversion Total Joint Arthroplasty: A Single-Institution Experience.

Background: With hospital inpatient capacity increasingly limited and primary total joint arthroplasty (TJA) rapidly transitioning to outpatient settings, the feasibility of outpatient aseptic revision and conversion TJA (rTJA) has been considered. Before the widespread adoption of outpatient rTJA, guidelines must be established to prevent patient harm. To this end, this study describes our initial experience with same-day-discharge (SDD) aseptic rTJA. Methods: All aseptic rTJAs performed between May 8, 2015, and December 30, 2021, were retrospectively reviewed. Revision indications, patient selection criteria, and outcomes including SDD success rate, predischarge complications, all-cause emergency department visits, inpatient readmissions, and unplanned clinic encounters within 90 days of surgery were recorded. Results: Thirty-five SDD aseptic rTJAs were performed. Conversion total hip arthroplasty (55.0%) and instability (27.3%) were the most common indications for hip revision. Instability (50%) and conversion total knee arthroplasty (20.8%) were most common for knee revision. SDD was achieved in 97% (34/35) of cases. One hip patient failed SDD due to persistent hypoxia requiring an overnight hospital stay and also underwent closed reduction for dislocation in the emergency department within 90 days of discharge. Two additional patients had unplanned clinic encounters within 90 days of the index procedure. There were no hospital readmissions or reoperations within 90 days. Conclusions: Our initial experience suggests SDD aseptic rTJA can be safe and effective when modern perioperative outpatient protocols and surgical techniques are implemented. Future studies should further define patient selection criteria to optimize outcomes and minimize complications in this population.

Procedure Duration, Time Under Anesthesia, and Readmissions in Direct Anterior and Posterior Approach Total Hip Arthroplasty.

BACKGROUND: Operative time is related to complications in primary total hip arthroplasty (THA). This study compared operative time in direct anterior (DA) and posterior approach THA and whether differences were related to increased hospital readmissions within 90 days of discharge. METHODS: Prospectively documented data on 3,152 consecutively performed THAs by 16 surgeons at a large Midwestern United States academic healthcare system were retrospectively reviewed. All surgeons were beyond their learning curve. Cases characterized by factors extending operative time were excluded. A total of 1,235 analysis cases were performed with the DA approach and 1,608 with the posterior approach. DA patients had lower mean body mass index (P < .001), were more likely to be classified as American Society of Anesthesiologists Physical Status 1 or 2 (P < .001), and more likely to have surgery in an ambulatory setting (P < .001). RESULTS: Time under anesthesia was significantly longer for DA procedures by 19 to 27 minutes in hospital and ambulatory settings, respectively (P < .001). Increasing body mass index had a greater impact on anesthesia time for DA patients (P = .020). There were no differences in nontraumatic readmissions within 90 days of surgery based on surgical approach (P ≥ .480); however, significantly more DA patients classified as ASA-PS 3 or 4 were readmitted compared to those classified as ASA-PS 1 or 2 (P < .001), a difference not observed for posterior approach patients. CONCLUSION: Anesthesia time is a modifiable risk factor for patient safety and an important factor in healthcare resource utilization. Consideration of ways to reduce DA operative times is encouraged.

The Fate and Relevance of the Patella in Two-Stage Revision Total Knee Arthroplasty for Periprosthetic Joint Infection.

BACKGROUND: It remains unclear whether reimplantation of a patellar component during a two-stage revision for periprosthetic total knee arthroplasty infection (PJI) affects patient reported outcome measures (PROMs) or implant survivorship. The purpose of this study was to evaluate whether patellar resurfacing during reimplantation confers a functional benefit or increases implant survivorship after two-stage treatment for PJI. METHODS: Two-stage revisions for knee PJI performed by three surgeons at a single tertiary care center were reviewed retrospectively. All original patellar components and cement were removed during resection and the patella was resurfaced whenever feasible during reimplantation. PROMs, implant survivorship, and radiographic measurements (patellar tilt and displacement) were compared between knees reimplanted with a patellar component versus those without a patellar component. RESULTS: A total of 103 patients met the inclusion criteria. Forty-three patients (41.7%) underwent reimplantation with, and 60 patients (58.3%) without a patellar component. At a mean follow-up of 33.5 months, there were no significant differences in patient demographics or PROMs between groups (P ≥ .156). No significant differences were found in the estimated Kaplan-Meier all-cause, aseptic, or septic survivorship between groups (P ≥ .342) at a maximum of 75 months follow-up. There was no significant difference in the change (pre-resection to post-reimplant) of patellar tilt (P = .504) or displacement (P = .097) between the groups. CONCLUSION: Patellar resurfacing during knee reimplantation does not appear to meaningfully impact postoperative PROMs or survivorship. Given the risk of potential extensor mechanism complications with patellar resurfacing, surgeons may choose to leave the patella without an implant during total knee reimplantation and expect similar clinical outcomes. LEVEL OF EVIDENCE: Level III.

Tibiofemoral Contact Forces Influence Intraoperative Kinematic Pivot Pattern Dependent on Posterior Cruciate Ligament Resection in Primary Total Knee Arthroplasty.

BACKGROUND: Optimizing knee kinematics has the potential to increase patient satisfaction with total knee arthroplasty (TKA); however the ability to enact a particular kinematic pattern is variable and inconsistent. The purpose of this study was to determine whether intraoperative contact forces were predictive and can potentially drive a particular kinematic pivot pattern. METHODS: All TKAs used sensor-embedded tibial trials to intraoperatively measure medial and lateral compartment forces, and the associated condylar contact points were used to calculate kinematic pivot patterns between preceding flexion angles. RESULTS: After exclusions, 157 TKAs were analyzed. For posterior cruciate ligament-intact TKAs, no predictors of lateral pivot were identified in early flexion; however, increased medial compartment force and increased lateral compartment force were predictors of medial and lateral pivots for mid and late flexion, respectively (P ≤ 0.037). For posterior cruciate ligament-resected TKAs, increased lateral compartment force was a predictor of lateral pivot in early and midflexion (P ≤ 0.031) but not late flexion. CONCLUSION: The tibiofemoral compartment with greater contact force exhibited less anteroposterior translation at certain flexion ranges and correlated with kinematic pivot patterns. This information may benefit surgeons who are attempting to facilitate a particular kinematic pattern. Further research is recommended to confirm that intraoperative kinematics correlate with weight-bearing postoperative kinematics and clinical outcomes.

The AAHKS Clinical Research Award: Are Minimum Two-Year Patient-Reported Outcome Measures Necessary for Accurate Assessment of Patient Outcomes After Primary Total Knee Arthroplasty?

BACKGROUND: The two-year minimum follow-up after total knee arthroplasty (TKA) required by most academic journals is based on implant survivorship studies rather than patient-reported outcome measures (PROMs). Additionally, the COVID-19 pandemic placed an unprecedented burden on patients and staff and halted asymptomatic surveillance clinic visits to minimize exposure. The purpose of this study was to determine if clinically meaningful differences were observed in PROMs beyond one year after TKA. METHODS: A retrospective review was performed on prospectively collected PROMs after 1093 primary TKAs at a suburban academic center. PROMs related to pain, function, activity level, and satisfaction were compared by subsequent follow-up intervals preoperatively, at 4 months, 1 year, and minimum 2 years using paired data analysis techniques. RESULTS: Pain with level walking and while climbing stairs improved from preoperative levels to 4-month, 1-year, and minimum 2-year follow-up. The University of California Los Angeles activity level and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement improved over the same intervals. Patient satisfaction improved over postoperative follow-up intervals (84.0%, 87.3%, and 90.9%). While PROMs improved with statistical and clinical significance preoperatively to 4-month to 1-year follow-up, improvements from 1-year to minimum 2-year follow-up were small and did not reach minimum clinically important differences for nearly all PROMs, demonstrating significant overlap of the 95% confidence intervals. CONCLUSION: While long-term follow-up after TKA remains important for implant survivorship, it appears that one-year PROMs are as clinically reliable and meaningful as two-year PROMs. Therefore, it is reasonable to question the currently accepted 2-year minimum follow-up requirement used in peer-reviewed research involving PROMs. LEVEL OF EVIDENCE: Level III.

Time Required for Planned and Unplanned Episodes of Care in Septic Two-Stage Revision Hip and Knee Arthroplasty.

BACKGROUND: Septic revision total hip (rTHA) and knee (rTKA) arthroplasty requires more effort but is reimbursed less than primary procedures per minute of intraoperative time. This study quantified planned and unplanned work performed by the surgical team for septic 2-stage revision surgeries during the entire episode-of-care "reimbursement window" and compared that time to allowable reimbursement amounts. METHODS: Between October 2010 and December 2020 all unilateral septic 2-stage rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated over each episode of care, from surgery scheduling to 90 days postoperatively. Impromptu patient inquiries and treatments after discharge, but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient. RESULTS: Sixty-eight hips and 64 knees were included. For 2-stage rTHA and rTKA the average time per patient for planned care was 1728 and 1716 minutes and for unplanned care was 339 and 237 minutes. Compared to the Centers for Medicare and Medicaid Services' allowable reimbursement times, an additional 799 and 887 minutes of uncompensated time was required to care for 2-stage rTHA and rTKA patients. CONCLUSION: Two-stage revision procedures are substantially more complex than primary procedures. Financially disincentivizing surgeons to care for these patients reduces access to care when high-quality care is most needed. These findings support increasing the allowable times for 2-stage septic revision cases.

Reduced Infection Rate After Aseptic Revision Total Knee Arthroplasty With Extended Oral Antibiotic Protocol.

BACKGROUND: The optimal postoperative antibiotic duration has not been determined for aseptic revision total knee arthroplasty (R-TKA) where the risk of periprosthetic joint infection (PJI) is 3%-7.5%. This study compared PJI rates in aseptic R-TKA performed with extended oral antibiotic prophylaxis (EOAP) to published rates. METHODS: Aseptic R-TKAs consecutively performed between 2013 and 2017 at a tertiary care referral center in the American Midwest were retrospectively reviewed. All patients were administered intravenous antibiotics while hospitalized and discharged on 7-day oral antibiotic prophylaxis. Infection rates and antibiotic-related complications were assessed. RESULTS: Sixty-seven percent of the 176 analysis patients were female, with an average age of 64 years and body mass index of 35 kg/m2. Instability and aseptic loosening comprised 86% of revision diagnoses. Overall, 87.5% of intraoperative cultures were negative, and the remainder were single positive cultures considered contaminants. PJI rates were 0% at 90 days, 1.8% (95% confidence interval 0.4%-5.3%) at 1 year, and 2.2% (95% confidence interval 0.6%-5.7%) at mean follow-up of approximately 3 years (range, 7-65 months). CONCLUSION: EOAP after aseptic R-TKA resulted in a PJI rate equivalent to primary TKA, representing a 2- to-4-fold decrease compared with published aseptic R-TKA infection rates. Further study on the benefits and costs of EOAP after aseptic R-TKA is encouraged.

Relative Contribution of Outpatient Arthroplasty Risk Assessment Score Medical Comorbidities to Same-Day Discharge After Primary Total Joint Arthroplasty.

BACKGROUND: Selection of patients who can safely undergo outpatient total joint arthroplasty (TJA) is an increasing priority given the growth of ambulatory TJA. This study quantified the relative contribution and weight of 52 medical comorbidities comprising the Outpatient Arthroplasty Risk Assessment (OARA) score as predictors of safe same-day discharge (SDD). METHODS: The medical records of 2748 primary TJAs consecutively performed between 2014 and 2020 were reviewed to record the presence or absence of medical comorbidities in the OARA score. After controlling for patients not offered SDD due to OARA scores and patients who were offered but declined SDD, the final analysis sample consisted of 631 cases, 92.1% of whom achieved SDD and 7.9% of whom did not achieve SDD. Odds ratios were calculated to quantify the extent to which each comorbidity is associated with achieving SDD. RESULTS: Demographic characteristics of analysis cases were consistent with a high-volume TJA practice in a US metropolitan area. Among testable OARA comorbidities, 53% significantly decreased the likelihood of SDD by 2.3 (body mass index [BMI] ≥40 kg/m2) to 12 (history of post-operative confusion and pacemaker dependence) times. BMI between 30 and 39 kg/m2 did not affect the likelihood of SDD (P = .960), and BMI ≥40 kg/m2 had the smallest odds ratio in our study (2.28, 95% confidence interval 1.11-4.67, P = .025). CONCLUSION: Study findings contribute to the refinement of the OARA score as a successful predictor of safe SDD following primary TJA while maintaining low 90-day readmission rates.

Patellar tilt does not affect patient reported outcomes after modern total knee arthroplasty.

BACKGROUND: The focus of patella maltracking after total knee arthroplasty (TKA) has traditionally been on patella polyethylene damage and failure mechanisms rather than functional outcomes. The purpose of this study was to evaluate the effect of patellar tilt on patient reported outcomes (PROMS) after primary TKA performed with patellar resurfacing. METHODS: A retrospective review using a single implant design was performed. Patella tilt was radiographically measured according to a standardized protocol. PROMS related to pain, function, and satisfaction were evaluated preoperatively and at minimum 1-year follow-up. RESULTS: A total of 468 TKAs were included for analysis. Mean age and BMI were 64 years and 35 kg/m2; respectively while 63% of patients were female. The median follow-up period was 12.7 months. Overall, patellar tilt was corrected from a median of 5.0 degrees preoperatively to a median of 3.0 degrees postoperatively. Preoperative, postoperative, and the change in patellar tilt had no significant effects on PROMS at minimum 1-year follow-up (p ≥ 0.092). Satisfaction in knee function while getting out of bed was higher for patients with approximately the same patellar tilt before and after TKA compared to patients with an increase in lateral patellar tilt (95% vs 80%, p = 0.025). CONCLUSIONS: The range of patellar tilt studied in this cohort had little to no effect on PROMS. However, suboptimal patellar tracking may potentiate edge loading of the polyethylene and contribute to implant damage in the long-term. These results are helpful to focus efforts on the tibiofemoral articulation as the predominant determinant of patient outcomes.

Complications and Outcomes Associated With a Novel, Prefabricated, Articulating Spacer for Two-Stage Periprosthetic Joint Infection Treatment.

BACKGROUND: Various prefabricated articulating spacer options have been described for 2-stage treatment of chronic periprosthetic joint infection, but their results are poorly generalizable between designs due to differing antibiotic and material properties. This study reports outcomes for a novel, prefabricated, commercially available cement-on-cement articulating spacer. METHODS: A retrospective review of prospectively collected data for patients undergoing treatment with a prefabricated articulating cement spacer was performed. Outcomes were categorized as spacer complications, reimplantation rates, function, reinfection, and mortality. RESULTS: Seventy-six knees and 28 hips were analyzed. Spacer survival free of fracture, instability, or other implant-related complication until reimplantation was 100%. There were no bony or spacer fractures during the interstage or reimplantation. Reimplantation occurred in 84.6% of resected joints. Following spacer implantation, all but 1 patient was allowed to bear weight. The proportion of patients requiring an assistive device decreased from 67% prior to resection to 31% following reimplantation. Knee flexion improved from an average of 88.1° before resection to 111.9° following reimplantation. Eighty-seven percent of cases were infection free at mean follow-up of 16.6 ± 10.4 months. CONCLUSION: Study results demonstrate that this novel, prefabricated, articulating antibiotic spacer is safe, allows for good interstage function, and results in reasonable infection eradication rates at early term follow-up. LEVEL OF EVIDENCE: Therapeutic Level III.

The AAHKS Clinical Research Award: Extended Oral Antibiotics Prevent Periprosthetic Joint Infection in High-Risk Cases: 3855 Patients With 1-Year Follow-Up.

BACKGROUND: Surgical and host factors predispose patients to periprosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). While surgical factors are modifiable, host factors can be challenging, and there are limited data demonstrating that preoperative patient optimization decreases risk of PJI. The goal of this study was to evaluate whether extended oral antibiotic prophylaxis reduces the one-year infection rate in high-risk patients. METHODS: A total of 3855 consecutive primary THAs and TKAs performed between 2011 and 2019 at a suburban academic hospital with modern perioperative and infection-prevention protocols were retrospectively reviewed. Beginning in January 2015, a 7-day oral antibiotic prophylaxis protocol was implemented after discharge for patients at high risk for PJI. The percentage of high-risk patients diagnosed with PJI within 1 year was compared between groups that did and did not receive extended antibiotic prophylaxis. Univariate and logistic regression analyses were performed, with P ≤ .05 denoting statistical significance. RESULTS: Overall 1-year infection rates were 2.26% and 0.85% after THA and TKA, respectively. High-risk patients with extended antibiotic prophylaxis had a significantly lower rate of PJI than high-risk patients without extended antibiotic prophylaxis (0.89% vs 2.64%, respectively; P < .001). There was no difference in the infection rate between high-risk patients who received antibiotics and low-risk patients (0.89% vs 1.29%, respectively; P = .348) with numbers available. CONCLUSION: Extended postoperative oral antibiotic prophylaxis for 7 days led to a statistically significant and clinically meaningful reduction in 1-year infection rates of patients at high risk for infection. In fact, the PJI rate in high-risk patients who received antibiotics was less than the rate seen in low-risk patients. Thus, extended oral antibiotic prophylaxis may be a simple measure to effectively counteract poor host factors. Moreover, the findings of this study may mitigate the incentive to select healthier patients in outcome-based reimbursement models. Further study with a multicenter randomized control trial is needed to further validate this protocol. LEVEL OF EVIDENCE: Therapeutic level III.

Safety of Same and Next Day Discharge Following Revision Hip and Knee Arthroplasty Using Modern Perioperative Protocols.

BACKGROUND: Advances in perioperative care have enabled early discharge and outpatient primary total joint arthroplasty (TJA). However, the safety of early discharge after revision TJA (rTJA) remains unknown and the COVID-19 pandemic will force decreased hospitalization. This study compared 90-day outcomes in patients undergoing aseptic rTJA discharged the same or next day (early) to those discharged 2 or 3 days postoperatively (later). METHODS: In total, 530 aseptic rTJAs performed at a single tertiary care referral center (December 5, 2011 to December 30, 2019) were identified. Early and later discharge patients were matched as closely as possible on procedure type, sex, American Society of Anesthesiologists physical status classification, age, and body mass index. All patients were optimized using modern perioperative protocols. The rate of 90-day emergency department (ED) visits and hospital admissions was compared between groups. RESULTS: In total, 183 early discharge rTJAs (54 hips, 129 knees) in 178 patients were matched to 183 later discharge rTJAs (71 hips, 112 knees) in 165 patients. Sixty-two percent of the sample was female, with an overall average age and body mass index of 63 ± 9.9 (range: 18-92) years and 32 ± 6.9 (range: 18-58) kg/m2. There was no statistical difference in 90-day ED visit rates between early (6/178, 3.4%) and later (11/165, 6.7%) discharge patients (P = .214). Ninety-day hospital admission rates for early (7/178, 3.9%) and later (4/165, 2.4%) discharges did not differ (P = .545). CONCLUSION: Using modern perioperative protocols with appropriate patient selection, early discharge following aseptic rTJA does not increase 90-day readmissions or ED visits. As hospital inpatient capacity remains limited due to COVID-19, select rTJA patients may safely discharge home the same or next day to preserve hospital beds and resources for more critical illness.

Quadriceps Weakness After Single-Shot Adductor Canal Block: A Multivariate Analysis of 1,083 Primary Total Knee Arthroplasties.

BACKGROUND: Adductor canal blocks (ACBs) are commonly employed in multimodal pain control for total knee arthroplasty (TKA) and minimize motor blockade compared with femoral nerve blocks. Quadriceps weakness may be associated with ACBs. The purpose of this study was to quantify the prevalence of clinically relevant quadriceps weakness after a single-shot ACB and to identify the factors that are associated with its diagnosis. METHODS: The study group consisted of 1,083 retrospectively reviewed consecutive TKAs that were performed with ACBs at an academic hip and knee center. Quadriceps weakness was quantified with a standardized rating system during the initial physical therapy evaluation, and 23 potential covariates were analyzed. RESULTS: The prevalence of quadriceps weakness was 9%. Increasing the dose of the ACB anesthetic per unit of body mass index (BMI) increased the probability of quadriceps weakness by 5.0 times (95% confidence interval [CI], 1.9 to 13.3; p = 0.001). The highest probability of quadriceps weakness (52.9%) was associated with women who received the highest anesthetic dose per unit of BMI and an epinephrine extender but no corticosteroid extender. CONCLUSIONS: The optimal volume of local anesthetic in ACBs to maintain pain control while minimizing quadriceps weakness has not yet been defined. Our observation that quadriceps weakness was associated with increasing doses of ACB anesthetic per unit of BMI suggests that more than traditional structural canal-fill parameters (i.e., filling the distal aspect of the adductor canal without spreading to the femoral triangle) should be considered when choosing injectates and injectate volumes for ACBs. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.