Adequate Positioning of the Tibial Component Is Key to Avoiding Bearing Impingement in Oxford Unicompartmental Knee Arthroplasty

BackgroundBearing dislocation is a serious complication of unicompartmental knee arthroplasty (UKA) with the Oxford knee prosthesis equipped with a mobile bearing. We aimed to clarify the extent of intraoperative movement of the mobile bearing and its relationship with the positioning of prosthesis components in patients undergoing Oxford UKA.MethodsThis retrospective study included 50 patients (50 knees) who underwent Oxford UKA for anteromedial osteoarthritis or osteonecrosis of the knee. Intraoperative bearing movement was assessed at various angles of knee flexion (0°, 30°, 60°, 90°, and 120°). We stratified patients according to the extent of bearing movement posteriorly during intraoperative knee flexion, with or without contacting the lateral wall of the tibial component (with contact, 20 knees; without contact, 30 knees). Postoperative radiographic evaluations were conducted at 1 week postoperatively to assess the positional parameters of the tibial and femoral components (varus/valgus alignment, rotation, mediolateral position). Clinical evaluations were conducted at 1 year postoperatively (maximum flexion angle, Oxford Knee Score).ResultsAbnormal intraoperative movement of the mobile bearing resulting in contact with the lateral wall of the tibial component was associated with a significantly more medial position and external rotation of the tibial component, as well as poorer improvement in knee flexion angle at 1 year postoperatively.ConclusionIn Oxford UKA recipients, the bearing may impinge on the lateral wall of the tibial component during flexion above 60° if the tibial component is placed too medially or exhibits pronounced external rotation, which may limit knee function improvement postoperatively.     

Good Postoperative Flexion Angle Improves Knee Function and Improvement of Flexion Angle Increases Patient Satisfaction After Total Knee Arthroplasty

BackgroundTotal knee arthroplasty (TKA) is a well-established procedure for treating knee joint diseases. However, the postoperative range of motion (ROM) varies and is an important indicator of TKA success. Recently, patient-reported outcome measures (PROMs) and patient satisfaction have drawn attention. However, the relationship between ROM and knee function obtained by PROM and satisfaction is not well understood.MethodsWe retrospectively reviewed the data of 375 patients who underwent 500 primary TKA procedures. We measured the ROM before and after surgery. Knee joint function was evaluated using the Knee Injury Osteoarthritis Outcome Score, a PROM, and patients were classified into good function and poor function groups. Patient satisfaction was evaluated on a 5-graded scale as overall satisfaction, and patients were divided into a satisfied or a dissatisfied group according to the obtained scores. ROM was compared between the 2 groups, then significantly different factors were analyzed using multiple logistic regression analysis. Moreover, cut-off points of ROM for obtaining good function and patient satisfaction were determined using ROC curve analysis.ResultsThe postoperative flexion angle had a significant effect on knee function (P < .001). The cut-off value of the postoperative flexion angle for good knee function was 120°. The improvement in flexion angle had a significant effect on patient satisfaction (P = .004). The cut-off value for the improvement in the flexion angle was 5°.ConclusionThe postoperative flexion angle had a significant effect on knee function and improvement in the flexion angle had a significant effect on patient satisfaction.     

Valgus Subsidence of the Tibial Component Caused by Tibial Component Malpositioning in Cementless Oxford Mobile-Bearing Unicompartmental Knee Arthroplasty

BackgroundValgus subsidence (VS) of the tibial component is a rare complication of unicompartmental knee arthroplasty (UKA), and surgeons might consider revision surgery. The present study aimed to identify the factors related to VS of the tibial component after cementless Oxford mobile-bearing UKA.MethodsThe study included 120 patients who underwent Oxford mobile-bearing UKA using a cementless tibial component in our center between September 2015 and September 2016. Six showed VS of >2° after surgery. Patients were stratified into 2 groups according to the occurrence of VS of the tibial component (VS group, n = 6; no-subsidence group, n = 114). Postoperative radiographic evaluations were conducted to assess the varus/valgus alignment, rotation, and mediolateral position of the tibial and femoral components. The Oxford Knee Score (OKS) was assessed at 3, 6, and 12 months postoperatively. Positional parameters and sequential change in OKS were compared between the two groups using unpaired t-test (P < .05, statistically significant).ResultsAt 3 months postoperatively, an average VS of 3.4° in the VS group was observed, with a significant decrease in OKS. VS was associated with a significantly more medial position and external rotation of the tibial component. After 3 months, VS stopped, and the OKS gradually improved without revision surgery.ConclusionsVS might be caused by the malpositioning of the tibial component. VS of the tibial component after UKA appears to stop, with simultaneous pain relief, even without revision after 3 months postoperatively.     

Not Physical Activity,but Patient Beliefs and Expectations are Associated With Return to Work After Total Knee Arthroplasty

Background

After total knee arthroplasty (TKA), 17%-60% of the patients do not or only partially return to work (RTW). Reasons for no or partial RTW remain unclear, warranting further research. Physical activity (PA) has proven beneficial effects on work participation. Therefore, we hypothesized that preoperative PA is associated with RTW after TKA.

Association of the Psoas Muscle Index and Sagittal Spinal Alignment With Patient-Reported Outcomes After Total Hip Arthroplasty: A Minimum 5-Year Follow-Up

BackgroundThe aim of this study is to assess the association between a spinopelvic malalignment and patient-reported perception of the hip as being “artificial” after total hip arthroplasty (THA). This is a critical issue as an age-related spinopelvic mismatch has been postulated to be associated with the risk of poor outcomes after THA.MethodsThis is a retrospective case-control study of 274 THAs (244 of whom were women), with a mean follow-up of 6.2 (range 5.0-8.2) years. Hip perception was assessed by asking subjects whether their joint felt “natural” or “artificial.” The association between an artificial perception and the following factors was evaluated: age, gender, psoas muscle index (PMI, cross-sectional area of bilateral psoas at L3 divided by height squared), and spinopelvic measures using logistic regression analysis.ResultsAn artificial hip perception (130 hips, 47.4%) was associated with a lower PMI (P = .016), Hip Disability and Osteoarthritis Outcome Score Joint Replacement score (P = .035), EuroQol 5-Dimension score (P = .041), and a higher incidence of a pelvic incidence-minus-lumbar lordosis (PI–LL) mismatch >10° (P < .001). A flatback deformity (odds ratio 2.24, 95% confidence interval 1.22-6.31, P = .001) and PMI (odds ratio 0.61, 95% confidence interval 0.34-0.82, P = .012) were predictive of an artificial perception. With the threshold of PI–LL set to 10°, PMI (P = .034), Hip Disability and Osteoarthritis Outcome Score Joint Replacement score (P < .001), joint perception (P = .020), EuroQol 5-Dimension score (P = .028), pain (P = .031), and satisfaction (P < .001) differed between the 2 groups.ConclusionA flatback deformity is associated with the risk of an artificial perception post-THA, especially in patients with sarcopenia. PMI and PI?LL measurements may help predict THA outcomes.     

Robot-Assisted Total Knee Arthroplasty Does Not Improve Long-Term Clinical and Radiologic Outcomes

BackgroundWhether robot-assisted total knee arthroplasty (TKA) improves the accuracy of radiographic alignment leading to improved patient satisfaction and implant survivorship in the long term has thus far been inconclusive.MethodsWe retrospectively compared the long-term clinical and radiological outcomes of 84 knees that had undergone robot-assisted TKA using ROBODOC vs 79 knees that had undergone conventional TKA. The mean duration of the follow-up period was 129.1 months (range: 108-147 months). Clinical outcomes were evaluated using the Knee Society Score and 36-item Short Form Survey, as well as by assessing the range of motion, operation time, and complications. Radiologic outcomes were evaluated by assessing the hip-knee-ankle angle, coronal and sagittal alignments of the femoral and tibial components, and any radiologic abnormalities such as loosening or osteolysis.ResultsThere was no significant difference in clinical outcomes between the two groups. The prevalence of an outlier for the hip-knee-ankle angle in the robot-assisted group was 10.7%, whereas it was 16.5% in the conventional group (P = .172). The other component alignments (α°, β°, γ°, δ°) revealed a tendency toward a lower rate of outliers in the robot-assisted group, but without statistical significance (P > .05). In addition, there was no significant difference in complications, including revision surgery, between both groups.ConclusionRobot-assisted TKA does not improve long-term clinical or radiologic outcomes compared with conventional TKA.     

Patient-Specific Instrumentation Does Not Affect Rotational Alignment of the Femoral Component and Perioperative Blood Loss in Total Knee Arthroplasty: A Prospective,Randomized, Controlled Trial

BackgroundProposed aims of patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) are to improve accuracy of component alignment, while reducing blood loss and surgical time. The primary goal of this prospective, randomized, controlled, clinical trial is to verify whether PSI improves the rotational alignment of the femoral component in comparison to conventionally implanted TKA.MethodsOne-hundred thirty-three consecutive patients were assessed for eligibility. Block randomization was performed to allocated patients in the treatment (PSI) or control group. During hospital stay, surgical times were recorded, and total blood volume loss and estimated red blood cell were calculated. Two months after surgery, a computed tomography of the knee was obtained to measure femoral component rotation to the transepicondylar axis and tibial component slope.ResultsSixty-nine patients were enrolled. PSI did neither result in a significant improvement in femoral component rotation nor result in a reduction of outliers, as compared with conventional instrumentation.No significant improvement in terms of tibial slope, blood loss, total surgical time, and ischemia time could be identified. The number of tibial recuts required in the PSI group was significantly higher than in the control group (P = .0003).ConclusionPSI does not improve the accuracy of femoral component rotation in TKA in comparison to conventional instrumentation. Moreover, PSI did not appear to influence any of the other variables investigated as secondary goals by this study. The results of this study do not support its routine use during standard TKA.Level of EvidenceLevel I, randomized, controlled trial.     

Trends in Length of Stay and 30-Day Complications After Total Knee Arthroplasty: An Analysis From 2006 to 2016

BackgroundHospital length of stay (LOS) is a quality metric and target of recent efforts in the last decade to decrease healthcare costs and postoperative nosocomial complications after total knee arthroplasty (TKA). However, decreasing LOS has raised concerns of possible increased complication and readmission rates. We present a decade-long analysis in trends of LOS and 30-day complication and unplanned readmissions following TKA.MethodsThe National Surgical Quality Improvement Program registry was utilized to identify patients undergoing elective primary TKA between 2006 and 2016. Three cohorts of patients were created based on year of surgery (2006-2009 [N = 7111], 2010-2013 [N = 71,943], and 2014-2016 [N = 142,710]). Patient demographics, perioperative variables, LOS, 30-day postoperative complications, and readmission rates were analyzed between the 3 cohorts using bivariate and multivariate analyses.ResultsLOS decreased significantly over time when the 2006-2009 cohort (3.7 days) was compared to the 2010-2013 cohort (3.3 days, P < .001) and 2014-2016 cohort (3.0 days, P < .001). Similarly, there was a decrease in the rate of total 30-day complications in the 2006-2009 cohort (5.37%) compared to 2010-2013 (3.86%) and 2014-2016 (3.13%, P < .001), with significantly lower rates of deep vein thrombosis, sepsis, and urinary tract infection in the latter cohorts. Decreasing rates of 30-day readmission were also observed in the 2010-2013 cohort (3.63%) compared to 2013-2016 cohort (3.23%, P < .001).ConclusionIn the last decade, there has been a trend toward decreasing LOS after TKA. Despite concerns about early discharge, data from a national registry demonstrated a simultaneous decrease in total 30-day complication and readmission rates.Level of EvidenceIII, Retrospective cohort study.     

Psychological Distress Independently Predicts Prolonged Hospitalization After Primary Total Hip and Knee Arthroplasty

BackgroundThe purpose of this study was to investigate the effect of psychological distress on hospital length of stay (LOS) in joint arthroplasty (TJA).MethodsA retrospective review of 863 patients who underwent primary, unilateral TJA at a single tertiary academic center was performed. Two groups were compared: patients with or without psychological distress defined using the Short Form-12 mental component summary. The primary outcome was the rate of hospital LOS exceeding 2 days. Secondary outcomes were rates of in-hospital complications and 90-day emergency room visits and readmissions. Univariate and multivariate logistic regression analyses were performed.ResultsThe prevalence of psychological distress was 23%. The mean LOS was 2.44 days. Patients with psychological distress were younger (P < .0001) and more likely to have depression (P < .0001), lower educational attainment (P < .0001), smoke tobacco (P = .003), be Hispanic/Latino (P = .001), live alone (P = .001), and have higher rates of nonprimary osteoarthritis (P < .0001). After adjusting for these differences, psychological distress was an independent predictor of LOS > 2 days (P = .049 and .006 for total hip arthroplasty [THA] and total knee arthroplasty [TKA], respectively). There were no differences in the rates of in-hospital complications (P = .913 and .782 for THA and TKA, respectively), emergency room visits (P = .467 and .355 for THA and TKA respectively), or readmissions (P = .118 and .334 for THA and TKA, respectively).ConclusionPsychological distress is an independent predictor of prolonged hospitalization after primary TJA. The Short Form-12 mental component summary is a good screening tool for identifying patients with poor mental health who may not be appropriate candidates for outpatient surgery. Efforts to address psychological distress before surgery are warranted.     

Normal Pressure Hydrocephalus Is Associated With Increased Risks of Postoperative Complications Following Total Knee and Total Hip Arthroplasty

BackgroundNormal pressure hydrocephalus (NPH) has not been studied as a potential risk factor for postoperative complications after primary total knee (TKA) and total hip arthroplasty (THA).MethodsNearly 2000 patients with a diagnosis of NPH who underwent TKA or THA from 2005 to 2014 were identified in a national insurance database and compared to 10:1 matched controls using a logistic regression analysis.ResultsNPH was associated with an increased risk of hospital readmission, emergency room visit, and infection following TKA (odds ratio 1.48-2.70, all P < .01). NPH was associated with an increased risk of hospital readmission, emergency room visit, and dislocation following THA (odds ratio 2.40-2.50, all P < .01). NPH was also associated with significantly higher costs and hospital length of stay following both procedures.ConclusionThe diagnosis of NPH is associated with an elevated risk of postoperative complications and increased resource utilization following TKA and THA.     

Complications and Costs Are Not Increased After Total Hip Arthroplasty in Patients With a History of Prostate Cancer

BackgroundProstate cancer (PCa) is a largely prevalent disease in the United States. Moreover, it is unclear whether the thromboembolic burden of disease remains present after the cancer has been treated and whether such state impacts the short-term outcomes of orthopedic procedures. Therefore, the purpose of this study is to assess 90-day postoperative complications and costs after total hip arthroplasty (THA) for osteoarthritis in patients with a history of PCa.MethodsTwo groups of patients who underwent THA for osteoarthritis in the Medicare Standard Analytical Files were identified through the PearlDiver server. Both groups were matched based on age, diabetes, smoking status, chronic kidney disease, alcohol abuse, chronic liver disease, and obesity in order to create a case-control study comparison. The 90-day complication rates after THA were compared using univariate regressions (odds ratio). We hypothesized that patients with a history of PCa would develop increased rates of thromboembolic complications based on a prolonged procoagulative state.ResultsAfter matching, each group was comprised of 62,571 patients. Our findings identified greater 90-day pneumonia rates for those without a history of PCa (3.26% vs 2.68%; odds ratio, 0.82). All other complications including thromboembolic diseases were clinically comparable in both groups during the 90-day postoperative period. The charges and reimbursements for the 90-day period were also comparable.ConclusionIn our large case-control study of 125,142 patients, we found that patients with a history of PCa do not have increased risk of short-term complications after THA and that the mean 90-day reimbursements were similar for both groups at $14,153 for PCa patients and $14,033 for those without (P = .114).     

Severe Obesity Increases Risk of Infection After Revision Total Hip Arthroplasty

BackgroundThe increasing prevalence of obesity has resulted in an increased number of revision total hip arthroplasties (rTHAs) performed in patients with a high body mass index (BMI). The aim of this study is to evaluate whether obesity negatively affects (1) complication rate, (2) reoperation and revision rate, and (3) patient-reported outcome in rTHA.MethodsIn this registry-based study, we prospectively followed 444 rTHAs (cup: n = 265, stem: n = 57, both: n = 122) performed in a specialized high-volume orthopedic center between 2013 and 2015. The number of complications, and reoperation and revision surgery was registered until 5 years postoperatively. Oxford Hip Score (OHS) was evaluated preoperatively, and at 1 and 2 years postoperatively. Patients were categorized based on BMI to nonobese (<30 kg/m², n = 328), obese (30-35 kg/m², n = 82), and severe obese (≥35 kg/m², n = 34).ResultsSevere obese patients, but not obese patients, had higher risks of complications and re-revision than nonobese patients. In particular, the risk of infection following rTHA was higher in severe obese patients (24%) compared to nonobese patients (3%; relative risk, 7.7). Severe obese patients had overall poorer OHS than nonobese patients, but improvement in OHS did not differ between severe obese and nonobese patients. No differences between obese and nonobese groups on OHS were observed.ConclusionIn our study, severe obesity was associated with an increased risk of infection following rTHA. Patients with high BMI should be counseled appropriately before surgery.     

Early Experience and Results Using Patient-Reported Outcomes Measurement Information System Scores in Primary Total Hip and Knee Arthroplasty

BackgroundOur study determined if preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores could predict achieving minimum clinically important differences (MCIDs) in postoperative PROMIS scores after primary total hip and knee arthroplasty.MethodsNinety-three patients were administered the PROMIS Depression, Pain Interference, and Physical Function domains at their preoperative appointment and 6-week follow-up visit. MCIDs were drawn from existing literature for the PROMIS domains.ResultsThe MCID was achieved in 74% of patients for Pain Interference, 34% for Physical Function, and 24% for Depression. Our model could predict with 90% specificity which patients would meet MCID if their preop PROMIS Pain score was above 38, Physical Function score less than 19, or Depression score above 22.ConclusionPreoperative PROMIS Pain Interference, Physical Function, and Depression scores can predict achieving MCID in postoperative PROMIS scores.     

Alteration of Hindfoot Axis After Total Knee Arthroplasty

BackgroundIt has been shown that total knee arthroplasty (TKA) can correct the alignment of the lower limb, not only correcting the knee axis, but also affecting the alignment of the hindfoot. However, there is still not a significant amount of work in the literature.MethodsA prospective study was carried out in which 72 patients were radiographically (long axial view of the hindfoot) and clinically (American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale) evaluated before and 3 months after TKA. We investigated whether there were any significant associations between measurements of the axes, hindfoot angle, and AOFAS score with the type of deviation of the patient’s axis.ResultsFor the subgroups “hindfoot valgus-knee valgus,” “hindfoot valgus-knee varus,” and “hindfoot varus-knee valgus,” a reduction in angle after surgery was observed; for the cases “hindfoot varus-knee varus,” an increase in angle after surgery was observed. However, the Wilcoxon test showed that only the changes in the hindfoot axis of the “hindfoot varus-knee valgus” subgroup are statistically significant (P < .05). After surgery, the Wilcoxon test showed that the AOFAS score changes are statistically significant for all subgroups for which it was possible to perform the test (P < .05).ConclusionTKA promotes changes in the postoperative hindfoot axis, significantly in patients with knee valgus and hindfoot varus. In addition, TKA provides significant improvement in the postoperative AOFAS score.Level of EvidenceIIB.     

External Validity of a New Prediction Model for Patient Satisfaction After Total Knee Arthroplasty

BackgroundThe ability to identify patients at risk of dissatisfaction after total knee arthroplasty (TKA) remains elusive. This study’s purpose was to determine the external validity of a recently published prediction model for patient satisfaction (PMPS) with the hypothesis that it would achieve similar predictive success in our study sample.MethodsA 10-question PMPS statistically derived from 5 patient-reported outcome questionnaires was tested for external validity in this prospective cohort investigation. The PMPS incorporates gender, age, stiffness, noise, and pain catastrophizing, with a score of 20 or greater predictive of satisfaction. As in the original study, to determine satisfaction the 2011 Knee Society Score (KSS) satisfaction subscale was collected at 3 months postoperatively. Two hundred seventy-four patients were administered the PMPS preoperatively, and 145 patients completed the KSS at 3 months postoperatively (53.0% response rate; 59% female; age, 64.9; body mass index, 32.5). A Bland-Altman analysis to assess agreement was performed.ResultsOne hundred thirty-three patients (91.7%) were satisfied and 12 (8.3%) were dissatisfied based on their postoperative KSS. The mean difference between the PMPS and KSS was 3.6 ± 8, but with a 95% prediction interval of ?15.3 to 22.1 signifying almost no correlation. The PMPS did not predict any of the 12 dissatisfied patients postoperatively, and falsely predicted 5 patients to be dissatisfied of which 4 actually had a maximum postoperative KSS of 40.ConclusionA previously published, internally validated 10-question PMPS was unable to predict satisfaction after TKA in our external study sample. This study emphasizes the difficulty of developing a simple, but robust questionnaire that consistently predicts patient satisfaction after TKA.     

Comparison of Expectations and Outcomes in Rheumatoid Arthritis Versus Osteoarthritis Patients Undergoing Total Knee Arthroplasty

BackgroundWe hypothesized that patients undergoing primary total knee arthroplasty (TKA) for rheumatoid arthritis (RA) would have different preoperative expectations compared to osteoarthritis (OA) patients, and that postoperative satisfaction would correlate with specific postoperative pain and functional domains.MethodsThis is a retrospective cohort study of RA patients matched based on age, gender, American Society of Anesthesiologists score, and Charlson Comorbidity Index score 1:2 with OA patients (76 RA, 152 OA) who underwent primary TKA. The Hospital for Special Surgery Knee Replacement Expectations Survey, Visual Analogue Scale for Pain (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), and the Short Form-12 (SF-12) were compared at baseline and at 2 years postoperatively. Minimum clinically important differences (MCIDs) were calculated for KOOS and SF-12 subdomains.ResultsPreoperatively, RA patients had lower expectations, worse VAS Pain, and worse KOOS Pain, Symptoms, and Activities of Daily Living (P < .05). However, at 2 years, RA patients had significantly larger improvements in VAS (P = .01) and these 3 KOOS subdomains (P < .05), achieving comparable absolute scores to OA patients. Overall, 86.1% of RA and 87.1% of OA patients were either somewhat or very satisfied with their TKA. Patient satisfaction correlated with VAS Pain and KOOS outcome scores in both groups. RA and OA patients had high rates of achieving MCID in SF-12 physical component scores and all 5 KOOS subdomains. A higher proportion of RA patients achieved MCID in KOOS Symptoms (98.4% vs 77.2%, P < .001).ConclusionRA patients had lower baseline expectations compared to OA patients. However, RA patients had greater improvements in KOOS and SF-12 subdomains, and there was no difference in satisfaction compared to OA patients after TKA.     

Improved Range of Motion and Patient-Reported Outcome Scores With Fixed-Bearing Revision Total Knee Arthroplasty for Suboptimal Axial Implant Rotation

BackgroundSuboptimal implant rotation has consequences with respect to knee kinematics and clinical outcomes. We evaluated the functional outcomes of revision total knee arthroplasty (TKA) for poor axial implant rotation.MethodsWe retrospectively reviewed 42 TKAs undergoing aseptic revision for poor axial implant rotation. We assessed improvements in Knee Society Score (KSS) and final range of motion (ROM). Subgroup analyses were performed for preoperative instability and stiffness, as well as the number of components revised and level of implant constraint used.ResultsRevision for poor axial rotation in isolation improved KSS from 52 ± 22 to 84 ± 25 (P < .001), and flexion increased from 105 ± 21° to 115 ± 13° (P = .001). Revision in the setting of instability significantly improved the KSS (P < .001) but did not affect ROM (P = .172). Revision in the setting of stiffness significantly improved both KSS (P < .001) and ROM (P = .002). There was no statistically significant difference between the postoperative KSS (P = .889) and final knee flexion (P = .629) with single- or both-component revision TKA for isolated poor axial rotation or between the postoperative KSS (P = .956) and final knee flexion (P = .541) with or without the use of higher constraint during revision TKA for isolated poor axial rotation.ConclusionRevision TKA for poor axial alignment improves clinical outcomes scores and functional ROM.     

Gender Differences for Hip and Knee Arthroplasty: Complications and Healthcare Utilization

IntroductionThe influence of patient gender on complications and healthcare utilization remains unexplored. The purpose of the present study was to determine if patient gender significantly affected outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsRetrospective cohort study of THA and TKA patients was performed using the Nationwide Inpatient Sample from 2002 to 2011. Only patients who underwent elective procedures and those with complete perioperative data were included. Multivariate logistic regression was used to compare the rates of adverse events between male and female cohorts while controlling for baseline characteristics.ResultsA total of 6,123,637 patients were included in the study (31.2% THA and 68.8% TKA). The cohort was 61.1% female. While males had a lower rate of any adverse event (odds ratio [OR] = 0.8, P < .001), urinary tract infection (OR = 0.4, P < .001), deep vein thrombosis/pulmonary embolism (OR = 0.9, P < .001), and blood transfusion (OR = 0.5, P < .001), male gender was associated with statistically significant increases in the rates of death (OR = 1.6, P < .001), acute kidney injury (OR = 1.6, P < .001), cardiac arrest (OR = 1.7, P < .001), myocardial infarction (OR = 1.6, P < .001), pneumonia (OR = 1.1, P < .001), sepsis (OR = 1.6, P < .001), surgical site infection (OR = 1.4, P < .001), and wound dehiscence (OR = 1.4, P < .001).ConclusionMales had increased rates of many individual adverse events. Females had higher rates of urinary tract infection, which translated to an overall higher rate of adverse events in females because of the rarity of the other individual adverse events.