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.

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.

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.

Time Required for Planned and Unplanned Episodes of Care in Primary Total Joint Arthroplasty: Has Anything Changed With a Growth in Outpatient Arthroplasty?

BACKGROUND: This study sought to determine the total amount of time committed to planned and unplanned episodes of care related to primary, unilateral total joint arthroplasty (TJA), relative to a growth in outpatient TJA. METHODS: All primary, unilateral TJA procedures performed over a 7-year period 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. All telephone inquiries and readmissions involving the surgeon's direct input, over the episode of care, constituted time dedicated to unplanned work. RESULTS: Between 2012 and 2018, as the proportion of outpatient TJAs increased, the average planned episode-of-care time per patient decreased from 412 minutes to 361 minutes. Despite a 108% increase in the total number of outpatient TJAs between 2017 and 2018 (51/432 (11.8%) to 106/555 (19.1%); P = .002), neither the average number of unplanned telephone inquiries (4.6 ± 3.8 vs 4.2 ± 3.7; P = .124), nor the mean time per patient required to respond to calls (23.1 ± 19.4 vs 21.2 ± 18 minutes, P = .135) differed. Between 2017 and 2018, the average total episode-of-care time per patient decreased from 403 minutes (376 planned + 27 unplanned) to 387 minutes (361 planned + 26 unplanned). CONCLUSION: Despite an increase in outpatient TJA, the average time required for planned and unplanned patient care remained relatively constant. The growth of outpatient TJA nationally should not trigger a change in Centers for Medicare and Medicaid Services benchmarks.

Greater Blood Loss in Contemporary Cementless Total Knee Arthroplasty than Cemented Total Knee Arthroplasty despite Tranexamic Acid Use: A Match-Controlled Retrospective Study.

The purpose of this retrospective study was to assess whether tranexamic acid (TXA) reduces blood loss in cementless total knee arthroplasty (TKA) comparable to levels observed with cemented fixation. After exclusions from 109 consecutive TKAs, 76 cementless knees were matched to 78 cemented knees of identical implant and surgeon. Blood loss with and without TXA was compared. There was no difference between cohorts in sex, age, body mass index, American Society of Anesthesiologists Physical Status classification, or preoperative hemoglobin (p ≥ 0.119). Use of TXA reduced median drain output by only 205 mL in cementless knees compared to 470 mL in cemented knees (p < 0.001). Median drain output per hour was highest in cementless knees without TXA (39.5 mL) followed by cemented knees without TXA (38.2 mL), cementless knees with TXA (28.5 mL), and cemented knees with TXA (12.7 mL; p < 0.001). Hemoglobin drop and total blood loss did not differ between cohorts regardless of TXA use. Cementless fixation in TKA resulted in greater intra-articular blood loss as measured by drain output, despite the use of TXA. Further research is warranted to examine whether a higher TXA dose, TXA delivery method, or the application of bone wax sealant would mitigate blood loss in cementless TKA, and subsequently whether intra-articular blood accumulation resulting in postoperative hemarthrosis affects recovery, function, and clinical outcomes.

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.

Satisfaction and Functional Outcomes in Unicompartmental Compared with Total Knee Arthroplasty: Radiographically Matched Cohort Analysis.

Unicompartmental and total knee arthroplasty (UKA and TKA) have demonstrated excellent mid- and long-term outcomes and have been compared in clinical series for decades; however, to our knowledge, no study has sufficiently matched UKA and TKA cohorts on preoperative osteoarthritis severity. The purpose of this study was to evaluate patient-reported outcomes of radiographically and demographically matched UKA and TKA cohorts. METHODS: One hundred and thirty-five UKAs and 135 TKAs were matched by patient age, sex, body mass index, and American Society of Anesthesiologists Physical Status (ASA-PS) classification as well as preoperative osteoarthritis severity in medial and lateral tibiofemoral and patellofemoral compartments (Kellgren-Lawrence grading system). Patient-reported outcome measures for pain, function, activity level, and satisfaction were evaluated at minimum 1-year follow-up via components of the modern Knee Society Score, the University of California Los Angeles (UCLA) activity-level score, and a Likert satisfaction scale. RESULTS: The patients in the UKA group reported significantly less pain, a higher activity level, and greater satisfaction while performing several functional activities and could walk for a longer amount of time before stopping due to knee discomfort compared with those in the TKA group (p ≤ 0.038). In addition, a greater proportion of patients in the UKA than in the TKA group were "satisfied or very satisfied" with their knee replacement surgery at minimum 1-year follow-up (90% versus 81%; p = 0.043). CONCLUSIONS: With minimum 1-year follow-up, patients who underwent UKA reported significantly higher function, less pain, and a greater level of patient satisfaction than a radiographically and demographically matched TKA cohort. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Contemporary 2-Stage Treatment of Periprosthetic Hip Infection with Evidence-Based Standardized Protocols Yields Excellent Results: Caveats and Recommendations.

BACKGROUND: This study quantified the effectiveness of contemporary and evidence-based standardized 2-stage treatment for periprosthetic hip infection. Findings illustrate potential limitations of criticisms of 2-stage protocols and potential consequences of adopting single-stage protocols before definitive data are available. METHODS: Fifty-four consecutive hips treated with 2-stage resection and reimplantation were retrospectively reviewed. Standardized protocols were adhered to including implant resection, meticulous surgical debridement, antibiotic spacer, 6-week intravenous antibiotics, a 2-week drug holiday, and laboratory assessment of infection eradication before reimplantation. After reimplantation, patients were placed on prophylactic intravenous antibiotics until discharge and discharged on oral antibiotics for a minimum of 7 days until intraoperative cultures were final. Successful treatment was defined per Delphi-based International Multidisciplinary Consensus. RESULTS: The overall treatment success rate was 95.7% (44 of 46 cases) with mean infection-free survivorship of 67.2 (range, 23.8-106.4) months. Success rates were 100% for early and acute hematogenous infections regardless of host type and 100% for chronic infections in uncompromised hosts. 95% (19/20) of chronic infections in compromised hosts and 83.3% (5/6) of chronic infections in significantly compromised hosts were successfully treated. About 4% of primary hips and 20% of revision hips required repeat debridement and spacer exchange after initial resection. No patients died because of treatment. CONCLUSION: Details from this consecutive series of patients undergoing 2-stage treatment for hip infection suggest that some criticisms of 2-stage treatment as well as some arguments in support of single-stage treatment may be overstated. Promotion and uncritical adoption of single-stage treatment protocols are discouraged until further and more definitive data exist.

Dual-pivot bearings improve ambulation and promote increased activity levels in Total knee arthroplasty: A match-controlled retrospective study.

BACKGROUND: Modern understanding of native knee kinematics reveals more complex pattern of lateral-pivot in early flexion activities, and medial-pivot in deeper flexion (i.e. dual-pivot). The purpose of this study was to compare patient outcomes with a contemporary dual-pivot TKA, designed to replicate anterior-cruciate substitution and stability, with a traditional TKA. METHODS: One hundred and eighty-three dual-pivot TKAs were matched with 183 traditional non-conforming TKAs. All TKAs were cemented and performed with identical perioperative protocols. Patients were matched on age, sex, BMI, and ASA score. Patient-reported outcome measures were prospectively obtained and compared at minimum one-year follow-up. RESULTS: Study cohorts were identical with 72% female, average age of 68 years, and BMI of 33 kg/m2. There were no differences in prevalence of fibromyalgia, depression, preoperative narcotic use, or femoral component alignment (p ≥ 0.105). Dual-pivot TKA patients had a greater prevalence of lumbar spine disease (p = 0.012) and more reported their knee never feels normal preoperatively (p = 0.012). Dual-pivot TKA patients reported less walking pain at latest follow-up (p = 0.022). Trends for greater level of participation in very active activities or impact sports (p = 0.067) and more reporting their knee feels normal (p = 0.091) were observed in dual-pivot TKAs. CONCLUSION: Patients with dual-pivot knees reported less walking pain despite greater lumbar spine disease, supporting the potential benefit of lateral-pivot motion in early flexion activities. However, the groups were similar in overall satisfaction suggesting the nuances and potential ceiling-effect of patient satisfaction warrants further study.

An Experienced Surgeon Can Meet or Exceed Robotic Accuracy in Manual Unicompartmental Knee Arthroplasty.

BACKGROUND: Reports in the literature indicate that implant placement is more accurate with robotic-assisted unicompartmental knee arthroplasty (UKA); however, these studies have not always accounted for surgeon experience. The purpose of the present study was to compare the accuracy of tibial component alignment in UKA between an experienced high-volume surgeon and the published data on robotic-assisted surgery. METHODS: The radiographs made before and after 128 consecutive medial UKAs performed manually by a single surgeon using a cemented fixed-bearing implant were reviewed. Native tibial and tibial implant slope and varus alignment of the tibial implant were measured on preoperative and postoperative lateral and anteroposterior radiographs, respectively. The percentages of knees in which the postoperative measurements were within preoperative targets and the root mean square (RMS) error rates between the planned and achieved targets were compared with published robotic-assisted-UKA data. RESULTS: In the present study, the proportion of manual UKAs in which the tibial component alignment was within the preoperative target was 66% (85 of 128), which exceeded published values in a study comparing robotic (58%) with manual (41%) UKA. The RMS error for tibial component alignment in the present study (1.48°) was less than published RMS error rates for robotic UKAs (range, 1.8° to 5°). Fifty-eight percent (74) of the 128 study UKAs were within the surgeon's preoperative goal for tibial slope, which was closer to the published value of 80% for robotic UKAs than is the published rate of 22% for manual UKAs. The RMS error for tibial slope in the study UKAs (1.50°) was smaller than the published RMS error rates for tibial slope in robotic UKAs (range, 1.6° to 1.9°). CONCLUSIONS: Accurate implant alignment is important in UKA. In this study, an experienced surgeon achieved or exceeded robotic accuracy of tibial implant alignment in UKA. However, the relationship between implant position and patient outcomes is unknown, and a consensus on ideal surgical targets for optimal implant survivorship has yet to be established. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Do Antibiotic Intramedullary Dowels Assist in Eradicating Infection in Two-Stage Resection for Septic Total Knee Arthroplasty?

BACKGROUND: Evidence suggests approximately 40% of intramedullary (IM) canals are culture positive at resection for infected knee arthroplasty. While commonly utilized, no clinical data on the efficacy of antibiotic-eluding IM dowels exist. We quantified treatment success with and without the use of antibiotic-eluding IM dowels in two-stage treatment of periprosthetic knee infection using static and articulating antibiotic cement spacers. METHODS: 109 consecutive patients who underwent two-stage treatment for periprosthetic knee infection were reviewed. Treatment failure, defined as repeat resection before reimplantation or recurrent infection within 6 months of reimplantation, was evaluated based on spacer type and use of IM dowels, accounting for infection type and systemic host and local extremity grade. RESULTS: After exclusions for confounds, articulating spacers without IM dowels were used in 49 (57.7%) cases, articulating spacers with IM dowels in 14 cases (16.5%), and static spacers with IM dowels in 22 (25.9%) cases. Treatment success regardless of infection classification was 85.7% for articulating spacers with IM dowels, 89.8% for articulating spacers without IM dowels, and 68.2% for static spacers with IM dowels (P = .074). In chronically infected poor hosts with compromised extremities, treatment success remained highest in patients with articulating spacers with (90.9%) or without (92.9%) IM dowels compared with static spacers with IM dowels (68.4%) (P = .061). CONCLUSION: Findings suggest that the use of IM dowels did not enhance infection eradication above and beyond that observed for articulating spacers alone, including in the worst cases involving chronically infected poor hosts with compromised extremities.

Predictors of Outcomes and Complications After Microsurgical and Endovascular Treatment of 1300 Intracranial Aneurysms.

BACKGROUND: We performed a rigorous statistical analysis of the complications and outcomes of patients with ruptured or unruptured intracranial aneurysms. Our emphasis was on the potential predictive factors when both surgical and endovascular management are offered by a team with balanced microsurgical and endovascular expertise. METHODS: From January 2005 to December 2011, 1297 consecutive patients presenting with ruptured (n=829) or unruptured (n=468) aneurysms were prospectively enrolled in our vascular database. The treatment modality was determined by consensus of the endovascular and microsurgical teams. The patients' medical and neurological conditions and aneurysm characteristics were compared against the postintervention complication rates and outcomes using multivariate analyses. RESULTS: The patients mostly underwent clipping for ruptured (63.7%) or unruptured (56.6%) aneurysms. For ruptured aneurysms, higher Hunt and Hess and Fisher grades on admission were key predictors of increased neurological (P < 0.001 and P < 0.001, respectively) and medical (P < 0.001 and P=0.041, respectively) complication rates. No significant differences in the outcomes were observed between the coiling or clipping groups during the follow-up period. For the unruptured group, a family history of intracranial aneurysms was the most relevant predictor for reducing neurological complication rates and increasing survival at 6 months. Hypertension was, however, the strongest factor associated with complications negatively affecting the outcomes. CONCLUSIONS: For the ruptured and unruptured groups both, the outcomes were generally good, although neurological and medical complications were reasonably more frequent for the ruptured aneurysms. Coiling provided a sustained benefit in lowering the complication rates only in the short term for the unruptured aneurysms. Smoking was associated, paradoxically, with improved outcomes.

Identifiable Risk Factors to Minimize Postoperative Urinary Retention in Modern Outpatient Rapid Recovery Total Joint Arthroplasty.

BACKGROUND: Postoperative urinary retention (POUR) following total joint arthroplasty (TJA) presents a significant barrier to outpatient and early discharge TJA. This study examined the incidence and risk factors for acute POUR in a modern, evidence-based, outpatient, and early discharge TJA program. METHODS: Prospectively recorded data on 685 consecutive primary unilateral TJAs discharged the day of or day after surgery were retrospectively reviewed. POUR was diagnosed by a perioperative internal medicine specialist. Univariate analysis of potential predictors was performed, followed by binary logistic regression (BLR) testing of predictors with P ≤ .25. RESULTS: After exclusions for confounds, the final analysis sample consisted of 633 procedures. The overall incidence of POUR was 5.5% (3.9% for same day discharges). Male gender, history of urinary retention, use of rocuronium, use of glycopryrrolate, use of neostigmine, fentanyl spinals, and the absence of an indwelling urethral catheter were associated with acute POUR and met criteria for entry into multivariate BLR. Seventeen additional predictors, including kidney disease and outpatient surgery were unrelated to POUR. In the final BLR model (P = .001), male patients who received glycopyrrolate with neostigmine had a 34% probability of developing POUR, which declined to 2.8% in the absence of these risk factors. CONCLUSION: Despite a relatively low incidence of 5.5%, avoidance of anticholinergics and cholinesterase inhibitors during anesthesia should be carefully considered in outpatient TJA, particularly in stand-alone ambulatory surgery centers.

Outpatient Joint Arthroplasty-Patient Selection: Update on the Outpatient Arthroplasty Risk Assessment Score.

BACKGROUND: The Outpatient Arthroplasty Risk Assessment (OARA) score was designed to identify patients medically appropriate for same- and next-day discharge after surgery. The purpose of this study was to update and confirm the greater predictive utility of the OARA score in relation to American Society of Anesthesiologists Physical Status (ASA-PS) classification for same-day discharge and to identify the optimal preoperative OARA score for safe patient selection for outpatient surgery. METHODS: The perioperative medical records of 2051 primary total joint arthroplasties performed by a single surgeon at an academic tertiary care hospital were retrospectively reviewed. Six statistical measures were calculated to examine OARA score performance in binary classification of successful same-day discharge and preoperative OARA scores equal to 0 to 59 points (yes vs no) vs 0 to 79 points (yes vs no). RESULTS: Mean OARA scores increased more sharply in magnitude with increasing length of stay, providing superior discrimination than the ASA-PS classification with respect to same-day discharge. Preoperative OARA scores up to 79 points approached the desired 100% for positive predictive value (98.8%) and specificity (99.3%) and 0% for false positive rates (0.7%). CONCLUSION: The OARA score was designed to err in the direction of medical safety, and OARA scores between 0 and 79 are conservatively highly effective for identifying patients who can safely elect to undergo outpatient total joint arthroplasty. The ASA-PS classification does not provide sufficient discrimination for safely selecting patients for outpatient arthroplasty.