Dual Mobility Articulation in Total Hip Arthroplasty: Mixed Femoral and Acetabular Components are a Feasible Option.

BACKGROUND: The utilization of a different manufacturer for the prosthetic femoral head and the polyethylene insert in dual mobility (DM) for total hip arthroplasty (THA) may be necessary, especially in the revision setting. However, there is no data in the literature about this application. This study evaluated the outcomes of mixed manufacturer components, with the hypothesis that there would be no difference in measured outcomes compared to matched components. METHODS: The DM articulations implanted during THA revision were retrospectively reviewed from 2011 to 2017. The study group was then stratified into 2 cohorts: matching components or mixed components. Of 130 hips included in the study with DM articulations with average follow-up of 7 years, 103 had mixed and 27 had matching manufacturer components. Rates of all cause reoperation and revision, intraprosthetic dislocation, dislocation, and aseptic loosening were compared using Chi-squared and Fisher's exact test; survival analysis was also performed. RESULTS: Matched and mixed manufacturer implants had no significant difference between all cause reoperation (33 versus 25.2%), dislocation (14.8 versus 7.7%), and aseptic loosening (3.7 versus 3.9%), respectively. Higher rates of intraprosthetic dislocation (11 versus 0.97%) were observed in the matching component cohort. Survival analysis showed similar outcomes at 2, 5, and 10 years. CONCLUSIONS: Mixed-component DM articulations show similar results compared to matching components. The off-label use of mixed manufacture DM articulation in THA is a feasible and safe option in the correct patient. Furthermore, when encountering a well-fixed femoral stem or acetabular shell, the use of a mixed component DM articulations may reduce the morbidity for the patient and prevent revision of all components.

Decreasing Hip Offset in Total Hip Arthroplasty Results in Decreased Physical Function Scores.

BACKGROUND: Acetabular and femoral offset play an important role in total hip arthroplasty (THA) for postoperative stability and biomechanical function. However, it is unknown whether offset impacts patient-reported outcomes (PROs). This study evaluated patients undergoing direct anterior (DA) THA with the hypothesis that patients who have a decrease in hip offset postoperatively would have lower physical function scores and higher pain interference. METHODS: There were 499 patients who underwent DA THA at a single tertiary academic institution who were retrospectively evaluated. Preoperative and postoperative hip offset was measured by 2 reviewers using the Sundsvall method on standing anteroposterior pelvis radiographs. Postoperative changes in hip offset were categorized as increased (> 5 mm), matched (within 5 mm of the preoperative offset measurement), or decreased ( >5 mm). Postoperative PROs with a minimum 1-year follow-up were recorded. A one-way analysis of variance was utilized to compare postoperative pain and PROs between groups. RESULTS: Patients who had decreased offset had the lowest mean postoperative physical function scores at 39.4 (8.0), followed by the increased offset group at 42.2 (10.4) and the matched offset group at 42.8 (9.8) (P < .01). There were significant differences in postoperative physical function scores between matched offset (42.8) and decreased offset (39.4) groups (P < .01), as well as between increased offset (42.2) and decreased offset (39.4) groups (P = .04). There was no difference between matched and increased offset cohorts. CONCLUSIONS: Our data suggests that reducing hip offset may result in worse physical function scores compared to those who have matched or increased hip offset. This should be considered intraoperatively, and efforts should be made to avoid reduced offset even in the presence of hip stability.

Timing of Renal Transplant Prior to Total Knee Arthroplasty Impacts 90-Day Postoperative Outcomes.

BACKGROUND: Renal transplant (RT) patients are at increased risk for complications after total knee arthroplasty (TKA); however, it is unknown if the time from RT to TKA influences such risks. This study evaluated RT patients undergoing primary TKA at various time intervals after transplant. We hypothesized that increased time between RT and TKA would decrease the risk of complications after TKA. METHODS: There were 499 RT patients in a national database undergoing subsequent primary TKA from 2010 to 2020. Patients were stratified by intervals of less than 1 year, between 1 and 2 years, and more than 2 years from RT to TKA. Medical complications up to 90 days, readmissions, and 2-year revisions were compared via univariable and multivariable analyses. RESULTS: Patients who underwent TKA less than 1 year after RT were associated with higher 90-day medical complications when compared to those who underwent TKA 1 to 2 years after RT (odds ratio [OR] 0.4, confidence interval [CI] 0.2 to 0.8, P = .01) and more than 2 years (OR 0.3, CI 0.2 to 0.7, P < .01) after RT. Acute kidney injury and blood transfusion were the most common complications. The TKAs performed 2 years after RT were less likely to have 90-day readmissions when compared to TKAs performed less than 1 year after RT (OR 0.4, CI: 0.2 to 0.9, P < .01). However, time from RT to TKA did not increase the risk of revision at 2 years (P > .30). CONCLUSIONS: Patients undergoing TKA within 1 year of RT have an increased risk of 90-day postoperative medical complications and readmissions, but the time interval from RT does not appear to affect revision risk. These findings suggest waiting 1 year after RT before proceeding with TKA may be advantageous.

Ultracongruent Polyethylene Liners Do Not Affect Survival of Total Knee Arthroplasty for Valgus Deformity.

BACKGROUND: Valgus knee deformity is observed in nearly 10% of patients undergoing total knee arthroplasty (TKA). The degree of polyethylene constraint required to balance a valgus knee remains controversial, and historically, posterior-stabilized (PS) designs have been favored. This study evaluated the survivorship of TKA done in valgus knees based on implant design and specifically compared posterior-stabilized (PS) and ultracongruent (UC) liners. METHODS: A total of 549 primary TKAs performed on valgus knees by fellowship-trained arthroplasty surgeons from 2013 to 2019 were reviewed. Demographics, comorbidities, degrees of preoperative deformity, implants used, and all-cause revisions until final follow-up were recorded. Cox regression analyses evaluated survival to all-cause revision in each cohort. The mean follow-up was 4.9 years (range, 2 to 9). RESULTS: There were 403 UC liners compared to 146 PS liners. There was no difference in patient age (68 versus 67 years; P = .30), body mass index (30.9 versus 30.4; P = .36), or degree of deformity (8.6 versus 8.8 degrees; P = .75) between the cohorts. At final follow-up, there were 5 revisions in the PS cohort (3.4%) versus 11 revisions in the UC cohort (2.7%) (P = .90). The most common reason for revision in both cohorts was periprosthetic joint infection (4 PS; 8 UC). Multivariable regression analyses controlling for age, body mass index, Elixhauser comorbidity score, sex, and degree of deformity demonstrated UC polyethylene liners were not associated with revision (hazard ratio 0.76; 95% confidence interval [CI] 0.26 to 2.21; P = .62). There was no difference in eight-year survivorship to all-cause revision, including aseptic and septic failure. CONCLUSIONS: Alternative polyethylene liners from the historically utilized PS liners for TKA for valgus deformity did not reduce survivorship. With modern polyethylene designs, UC inserts can be utilized for this deformity without increasing the risk of failure.

Revision Total Knee Arthroplasty With an Imageless, Second-Generation Robotic System.

BACKGROUND: Robotic-assisted total knee arthroplasty is increasingly used in revision total knee arthroplasty (rTKA), with imageless systems recently receiving Food and Drug Administration (FDA) approval. However, there remains a paucity of literature on the use of robotic assistance in revision total knee arthroplasty (TKA). This paper describes the imageless surgical technique for robotic revision TKA using a second-generation robotic system and details both intraoperative and 90-day outcomes. METHODS: This was a retrospective review of 115 robotic revision TKAs from March 2021 to May 2023 at 3 tertiary academic centers. Patient demographics, perioperative surgical data, and 90-day outcomes were collected. Pain and Patient-Reported Outcomes Measurement Information System scores preoperatively and postoperatively were recorded. All-cause reoperations at the final follow-up were detailed. The mean patient age was 65 years (range, 43 to 88), and 58% were women. The mean follow-up time was 13 months (range, 3 to 51). RESULTS: The most common indications for rTKA were instability (n = 37, 32%) and aseptic loosening (n = 42, 37%). There were 83 rTKAs to a posterior-stabilized liner, 22 to a varus-valgus constrained liner, and 5 to a hinged construct. The median polyethylene size was 11 (interquartile range, 10 to 13), and 93% of patients had their joint line restored within 5 millimeters of the native contralateral knee. Within the 90-day postoperative window, there were 8 emergency department visits and 2 readmissions. At the final follow-up, there were 5 reoperations and 2 manipulations under anesthesia. There were 4 patients who required irrigation and debridement after superficial wound dehiscence, and one had an arthrotomy disruption after a fall. CONCLUSIONS: This review demonstrates favorable intraoperative and 90-day outcomes and suggests that imageless robotic surgery is a promising modality in rTKA. Further studies comparing the longitudinal outcomes after robotic and conventional rTKA are warranted.

Does Femoral Stem Design Influence Periprosthetic Fracture Incidence and Morphology in Total Hip Arthroplasty?

BACKGROUND: As the incidence of total hip arthroplasty (THA) increases, the number of periprosthetic femur fractures (PFF) will also rise. The surgical approach and stem design have been shown to influence the rate of PFF. This study evaluated PFF in cementless THA done through the posterior approach and described how stem design influences intraoperative and early postoperative fracture incidence and morphology. METHODS: A retrospective review of 3,183 primary THAs for osteoarthritis from 2013 to 2021 was performed. Demographics, comorbidities, femoral stem designs, intraoperative and early postoperative PFFs (< 90 days), and aseptic femoral revisions were recorded. Stems were classified as single-wedge taper (Type 1), double-wedge taper (Type 2), or ream and broach (Type 3). There were 1,192 Type 1, 240 Type 2, and 1,726 Type 3 femoral stems. The PFF and aseptic femoral revisions were compared with univariable and multivariable analyses. Cox regression and Kaplan-Meier analyses evaluated survival to femoral revision. RESULTS: In this population, 25 patients (0.8%) had an intraoperative or early postoperative PFF. Patients who had PFFs were older (68 versus 63; P = 0.03) and more likely to be women (76 versus 24%; P = 0.02). Type 2 stems had a significantly higher incidence of all-cause PFFs when compared to Type 1 (3.6 versus 0.7%; P < 0.01) and Type 3 (3.6 versus 0.4%; P < 0.01) stems. Type 2 stems also had a higher incidence of Vancouver B2 PFFs when compared to Type 3 stems (0.8 versus 0.05%; P = 0.04). Stem design was not associated with PFF or all-cause femoral revision. There were no differences in survival to femoral revision. CONCLUSION: Double-wedge taper stems may be associated with increased intraoperative and early postoperative PFFs, including those requiring femoral stem revision. However, there was no statistically significant difference in late PFF, aseptic loosening, or femoral revision.

The Posterior Approach is Associated With Lower Total Encounter and 90-Day Costs When Compared to the Direct Anterior Approach.

BACKGROUND: The clinical impact of the surgical approach in total hip arthroplasty (THA) has been widely reviewed. This study evaluated the total encounter and 90-day costs of THA for 2 surgical approaches (posterior [P] and direct anterior [DA]) in 1 tertiary health system. METHODS: This is a retrospective review of 2,101 THAs (1,092 P and 1,009 DA) by 4 surgeons (2 with the highest volume of DA and P, respectively) from 2017 to 2022 at 1 academic center. Demographics, comorbidities, operative time, length of hospital stay, 90-day hospital returns, and complications were compared. The total encounter cost and 90-day postoperative cost were itemized. Multivariable regression analyses evaluated associations with increased cost at each time point. RESULTS: The DA cohort had a higher median encounter cost ($8,348.66 versus 7,332.42, P < .01), resulting from higher intraoperative (P < .01) and radiology (P < .01) expenses. Regression analyses demonstrated the DA was independently associated with increased encounter costs (odds ratio 1.1; 95% confidence interval 1.1 to 1.1; P < .01). There was a higher incidence of 90-day emergency department visits in the DA cohort (16 versus 12%, P = .02), with a trend toward increased readmissions. There was no difference in 90-day reoperations. Median 90-day cost was higher in the DA cohort ($126.99 versus 0.00, P < .01), and regression analyses demonstrated the DA had an association with increased 90-day cost (odds ratio 2.2; 95% confidence interval 1.5 to 3.0; P < .01). CONCLUSIONS: Despite a younger patient population, the DA was independently associated with increased encounter and 90-day costs in a single academic hospital system. This study may underestimate the cost difference, as capital costs such as specialized tables were not analyzed.

A Multicenter Prospective Investigation on Patient Physical and Mental Health After Girdlestone Resection Arthroplasty.

BACKGROUND: Girdlestone resection arthroplasty is a salvage procedure for hip periprosthetic joint infection (PJI) that controls infection and reduces chronic pain, but may result in limited postoperative joint function. The aim of this study was to assess physical function and mental health after Girdlestone. METHODS: This was a multicenter, prospective study evaluating patients with Girdlestone. The Prosthesis Evaluation Questionnaire (PEQ) and patient-reported outcomes measurement information system (PROMIS) global physical health and mental health surveys were administered postoperatively via telephone. The PEQ consists of four scales (ie, ambulation, frustration, perceived response, and social burden) with scores ranging from 0 to 10. The PROMIS measures generated T-scores (mean: 50, standard deviation: 10) that enable comparison to the general population. RESULTS: Thirty-five patients completed all surveys. The average time from procedure to survey completion was 6 years (range, 1 to 20). The median scores for the ambulation, frustration, perceived response, and social burden scales of the PEQ were 0.0 [interquartile range: 0-4.1], 6.0 [3.0-9.3], 9.0 [7.2-10.0], and 7.5 [4.3-9.5]. The median raw scores of the PROMIS global physical health and mental health were 11.91 [interquartile range: 9-14] and 14.0 [10.0-16.0]. These corresponded to average T scores of 39.7 (standard error : 4.3) for physical health and 46.1 (standard error: 3.8) for mental health, which were 10.3 points and 3.9 points below the average score in the United States general population, respectively. CONCLUSION: Girdlestone can have a substantial negative impact on physical functions; however, mental health and social interaction may be only moderately affected. These outcomes can be used to guide patient expectations, as this procedure may be necessary in certain salvage scenarios.

Cost Drivers in Two-Stage Treatment of Hip Periprosthetic Joint Infection With an Antibiotic Coated Cement Hip Spacer.

BACKGROUND: The current gold standard for treating chronic Periprosthetic Joint Infection (PJI) is a 2-stage revision arthroplasty. There has been little investigation into what specific patient and operative factors may be able to predict higher costs of this treatment. METHODS: An institutional electronic health record database was retrospectively queried for patients who developed a PJI after a total hip arthroplasty, and underwent removal of the prosthesis and implantation of an antibiotic-impregnated articulating hip cement spacer. Patient demographics, surgical variables, hospital readmissions, emergency department visits, and post-operative complications were collected. Total costs were captured through an internal accounting database through 2 years post-operatively. Negative binomial regressions were utilized for multivariable analyses. A total of 55 hips with PJI were available for cost analyses. RESULTS: A comorbidity index score was associated with a 70% increase (Odds Ratio (OR): 1.7 [1.18-2.5], P = .003) in total costs at 2-years. Illicit drug use was associated with a 70% increase in costs at 1-year post-operatively (OR 1.7 [1.18-2.5], P = .003). Metal-on-poly liners were associated with a 22% decrease in cost at 2-years post-operatively when compared to Cement-on-Bone articulating spacers, and Metal-on-poly -constrained liners accounted for 38% lower costs at 1-year (OR 0.62 [0.44-0.87], P = .004). Use of an intraoperative extended trochanteric osteotomy was associated with a 46 and 61% increase in cost at 1-year (OR 1.46 [1.14-1.89]) and 2-years (OR 1.61 [1.26-2.07], P < .001) post-operatively. CONCLUSION: Age, comorbidity index score, drug use, and extended trochanteric osteotomy were associated with increased costs of PJI treatment. This may be used to improve reimbursement models and target areas of cost savings.

The Removal of Total Hip Arthroplasty From the Inpatient-Only List has Improved Patient Selection and Expanded Optimization Efforts.

BACKGROUND: On January 1, 2020, the Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the Inpatient-Only (IPO) list. This study evaluated patient demographics and comorbidities, preoperative optimization efforts, and 30-day outcomes of patients undergoing outpatient THA before and after IPO removal. The authors hypothesized that patients undergoing THA post-IPO removal would have improved optimization of modifiable risk factors and equivalent 30-day outcomes. METHODS: There were 17,063 outpatient THAs in a national database stratified by surgery performed before (2015 to 2019: 5,239 patients) and after IPO (2020: 11,824 patients) removal. Demographics, comorbidities, and 30-day outcomes were compared with univariable and multivariable analyses. Preoperative optimization thresholds were established for the following modifiable risk factors: albumin, creatinine, hematocrit, smoking history, and body mass index. The percentage of patients who fell outside the thresholds in each cohort were compared. RESULTS: Patients undergoing outpatient THA post-IPO removal were significantly older; mean age 65 years (range, 18 to 92) versus 62 (range, 18 to 90) years (P < .01), with a higher percentage of American Society of Anesthesiologists scores 3 and 4 (P < .01). There was no difference in 30-day readmissions (P = .57) or reoperations (P = 1.00). A significantly lower percentage of patients fell outside the established threshold for albumin (P < .01) post-IPO removal, and trended towards lower percentages for hematocrit and smoking status. CONCLUSION: The removal of THA from the IPO list expanded patient selection for outpatient arthroplasty. Preoperative optimization is critical to minimize postoperative complications, and the current study demonstrates that 30-day outcomes have not worsened post-IPO removal.

Does Order of Operation Matter in Patients Who Have Concomitant Hip and Spine Pathology?

BACKGROUND: In patients, who have coexisting lumbar spine and degenerative hip disease, there remains uncertainty regarding whether hip or spine surgery should be performed first. We hypothesized that undergoing total hip arthroplasty (THA) would protect against subsequent lumbar spine surgery (LSS) in patients who have 'hip-spine syndrome.' METHODS: A retrospective cohort study was performed from 2013 to 2021 on patients who had radiographically-confirmed hip osteoarthritis and degenerative lumbar spine pathology, evaluated separately in spine and arthroplasty clinics prior to surgical intervention. Included patients ultimately underwent THA and/or LSS. The primary outcome was survivorship free of LSS or THA after the other was initially performed. RESULTS: Of 256 patients, 206 (80.5%) underwent THA first. Only 14 of 206 (6.8%) who underwent THA required subsequent LSS, while 31 of 50 (62%) who underwent LSS required subsequent THA, (P < .001). At 5 years, there was 93.9% survivorship-free of LSS in the THA first group, compared to 44.7% survivorship-free of subsequent THA in the LSS group. Multivariate analyses showed that patients who had THA first had lower odds of undergoing subsequent surgery (odds ratio [OR]: 0.61, CI: 0.52-0.70, P < .001) compared to those who underwent LSS first. Additionally, those who have higher initial Kellgren-Lawrence grade hip osteoarthritis had lower odds (OR: 0.94, CI: 0.89-0.99, P = .04), and those who have progressive neurologic deficits (OR: 2.64, CI: 1.89-3.7, P < .001) and neurogenic claudication (OR: 1.15, CI: 1.06-1.24, P = .001) had increased odds of undergoing subsequent LSS. CONCLUSION: Patients with 'hip-spine syndrome' may receive more initial benefit from undergoing THA, potentially reducing the subsequent need for LSS. The exceptions were those patients who had lower-severity hip osteoarthritis and symptoms of major spinal stenosis.

Accelerated Discharge After Aseptic Revision Total Hip Arthroplasty Does Not Predict Inferior 30-Day Outcomes.

BACKGROUND: Perioperative advancements have made outpatient primary total hip arthroplasty (THA) a viable option for patients. This study evaluated the feasibility of expedited discharge after revision THA and compared 30-day outcomes to patients who had prolonged inpatient hospitalizations. The authors hypothesized that expedited discharge would not result in inferior 30-day outcomes. METHODS: Aseptic revision THAs in a national database were reviewed from 2013 to 2020. THAs were stratified by hospital length of stay (LOS) more or less than 24 hours. Demographics, comorbidities, preoperative laboratory values, American Society of Anesthesiology (ASA) scores, operative times, components revised, 30-day readmissions, and reoperations were compared. Multivariable analyses evaluated predictors of discharge prior to 24 hours, 30-day readmissions, and reoperations. Of 17,044 aseptic revision THAs, 211 were discharged within 24 hours. RESULTS: Accelerated discharge patients were younger, mean age 63 years (range, 20-92) versus 66 years (range, 18-94) (P < .01) had lower body mass index, mean 28.7 (range, 18.3-46.4) versus 29.9 (range, 17.3-52.5) (P = .01), and ASA scores (ASA, 1-2; 40.4-57.8%) (P < .01). Components revised had no association with LOS (P = .39); however, operative times were shorter and mean 100 minutes (range, 35-369) versus 139 minutes (range, 24-962) (P < .01) in accelerated discharge patients. Accelerated discharge patients had lower readmission rates (P < .01) but no difference in reoperation rates (P = .06). CONCLUSION: Discharge less than 24 hours after revision THA is a feasible option for the correct patient and further efforts to decrease LOS should be evaluated.

Cutibacterium positive cultures in total joint arthroplasty: a comparison of the hip, knee, and shoulder.

PURPOSE: Cutibacterium spp. (formerly Propionibacterium) is a slow growing, Gram-positive, anaerobic bacteria and is an emerging clinical entity in prosthetic joint infection (PJI). This study compares the presentation, surgical management, and post-operative antibiotic therapy of patients with positive intraoperative cultures during revision total joint arthroplasty (TJA) of the hip, knee, and shoulder. METHODS: This was a retrospective cohort study of patients from 2014 to 2020 of 57 revision TJAs (27 total hip arthroplasty (THA), 17 total shoulder arthroplasty (TSA), and 13 total knee arthroplasty (TKA)) with intraoperative cultures positive for Cutibacterium at a tertiary academic centre. Patient demographics, pre-operative labs, radiographs, and aspirate results were collected. Intraoperative data was reviewed. Post-operative antibiotic therapy and repeat infections were recorded. Data was compared with univariate analyses. RESULTS: There was no significant difference in pre-operative lab values between the cohorts. All cohorts had > 58% radiographic lucency. Revision TSA patients had significantly fewer pre-operative aspirates. Six patients undergoing revision THA, three TKA and one TSA had a repeat infection requiring further surgery. Four in the THA cohort and one in the TKA cohort with repeat infections did not receive prolonged antibiotic therapy. CONCLUSION: Cutibacterium is an infectious agent that can present in an indolent fashion after TJA. It commonly causes progressive radiographic lucency. The workup and post-operative management differs in the hip, knee, and shoulder, which is likely due to existing literature guiding physician practice. In all joints, Cutibacterium is a virulent pathogen that can cause repeat infections requiring surgical treatment.

Investigating readmission rates for patients undergoing oncologic resection and endoprosthetic reconstruction for primary sarcomas and tumors involving bone.

BACKGROUND: Little is known about the drivers of readmission in patients undergoing Orthopaedic oncologic resection. The goal of this study was to identify factors independently associated with 90-day readmission for patients undergoing oncologic resection and subsequent prosthetic reconstruction for primary tumors involving bone. METHODS: This was a retrospective comparative cohort study of patients treated from 2008 to 2019 who underwent endoprosthetic reconstruction for a primary bone tumor or soft tissue tumor involving bone, as well as those who underwent a revision endoprosthetic reconstruction if the primary endoprosthetic reconstruction was performed for an oncologic resection. The primary outcome measure was unplanned 90-day readmission. RESULTS: A total of 149 patients were identified who underwent 191 surgeries were for a primary bone or soft tissue tumor. The 90-day readmission rate was 28.3%. Female gender, depression, higher tumor grade, vascular reconstruction, longer procedure duration, longer length of stay (LOS), multiple surgeries during an admission and disposition to a Skilled Nursing Facility were associated with readmission (p < 0.05). In a multivariate analysis, female sex, higher tumor grade and longer procedure duration were independently associated with risk of readmission (p < 0.05). CONCLUSIONS: Readmission rates are high following endoprosthetic reconstruction for Orthopaedic oncologic resections. Further work is necessary to help minimize unplanned readmissions.

Early Infection After Aseptic Revision Knee Arthroplasty: Prevalence and Predisposing Risk Factors.

BACKGROUND: Although patient factors have been associated with prosthetic joint infection (PJI) after primary total knee arthroplasty, there are insufficient data on the relationship of patient and technical factors with early PJI after aseptic revision. METHODS: This is a retrospective study of 157 aseptic revisions performed by 2 surgeons at 1 academic center. A negative intraoperative culture during revision surgery was required for inclusion. Mean follow-up time was 3.8 years (standard deviation 2.8). PJI was defined by positive aspiration or draining wound, and an additional operation within 1 year of aseptic revision. Patient demographics, medical comorbidities, and technical factors were reviewed. Data points were evaluated with univariate and adjusted multivariate regression analyses. RESULTS: The prevalence of PJI after aseptic revision was 9% (14/157). The most common organism was Staphylococcus aureus. Initial treatment included debridement and liner exchange (11) and antibiotic spacer (3). Two patients ultimately had an above-knee amputation. Univariate analysis showed a significant difference in preoperative anemia (P < .01), transfusion (P < .01), and diabetes (P = .05) between cohorts. There was no association among the length of surgery, use of a metaphyseal cone, or the number of components revised and PJI. Adjusted logistic regression demonstrated that preoperative anemia (P < .01) was a significant risk factor for PJI. CONCLUSION: The prevalence of early PJI was similar to other studies in the literature. Anemia was an independent predictor of PJI, while technical factors did not have an association. Medical optimization of patients should be considered prior to revision surgery.

Risk Factors for Delayed Discharge and Adverse Outcomes Following Outpatient Billed Total Knee Arthroplasty.

BACKGROUND: The volume of outpatient total knee arthroplasty (TKA) has increased with advances in perioperative protocols, patient selection, and recent policy changes regarding insurance authorization. This study analyzed 30-day outcomes from a national database to better understand risk factors for delayed discharge (length of stay [LOS] ≥1), readmission, and reoperation after outpatient TKA. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was utilized to collect TKA (CPT 27447) billed as outpatient surgery performed from 2013 to 2018. Patient demographics, comorbidities, and short-term outcomes were collected and compared in LOS 0 versus LOS ≥1 cohorts. Subgroup analysis was completed for TKA performed in 2018, after the Center for Medicare Services removal of TKA from the inpatient-only list. RESULTS: A total of 13,669 patients had outpatient TKA performed from 2013 to 2018. Most patients had LOS ≥1 day (77.1%). The LOS 0 cohort demonstrated a lower 30-day readmission rate (1.8%) compared to LOS ≥1 (2.8%), P > .01. Both groups demonstrated a low 30-day reoperation rate, LOS 0 (0.7%) and LOS ≥1 (1.1%), P = .05. Regression analysis demonstrated risk factors for LOS ≥1 day included COPD, ASA ≥3, age >75, and BMI >35 kg/m2. Regression analysis demonstrated male gender, age >75, ASA ≥3, and albumin <3.5 g/dL were risk factors for readmission. Hypertension was a risk factor for 30-day reoperation. CONCLUSION: Risk factors for LOS ≥1 day include age >75, ASA ≥3, BMI >35 kg/m2. In addition, BMI >35 kg/m2 was a risk factor for readmission and reoperation. These findings reinforce appropriate patient selection when considering outpatient TKA.

Preoperative Weight Loss and Postoperative Weight Gain Independently Increase Risk for Revision After Primary Total Knee Arthroplasty.

BACKGROUND: The current American Association of Hip and Knee Surgeons (AAHKS) guidelines recommend preoperative weight loss before total knee arthroplasty (TKA) in patients with body mass index (BMI) ≥40 kg/m2. However, there is a paucity of evidence on TKA outcomes after preoperative weight loss. This study therefore evaluated predictors of preoperative and postoperative BMI changes and their impact on outcomes after TKA. METHODS: This is a retrospective review of 3058 primary TKAs at an academic institution from 2015 to 2019. BMI was collected on the day of surgery. Preoperative and postoperative BMI at 6 months and 1 year were also obtained. BMI change of ≥5% was considered clinically significant. Mean follow-up was 3.2 years. Patient demographics, acute postoperative outcomes, and all-cause revisions were compared between patients who gained, lost, or maintained weight using univariate and multivariable analyses. RESULTS: Preoperative weight loss was predictive of postoperative weight gain (P < .001), and preoperative weight gain was predictive of postoperative weight loss (P < .001). Cox regression analysis revealed that ≥5% BMI loss preoperatively increased risk for all-cause revisions (P = .030), while ≥5% BMI gain postoperatively increased risk for prosthetic joint infections (P = .016). Patients who lost significant weight both before and after surgery had the highest risk for all-cause revisions (P = .022). CONCLUSION: Weight gain postoperatively was associated with inferior outcomes. Significant weight loss before surgery led to a "rebound" in weight gain, and independently increased risk for all-cause revision. Therefore, current recommendations for weight loss before TKA in morbidly obese patients should be re-evaluated.

Patterns and Predictors of Weight Change Before and After Total Hip Arthroplasty in Class 2 and 3 Obese Patients.

BACKGROUND: This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes. METHODS: We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI > 35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded. RESULTS: We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained >5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P < .001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes. CONCLUSION: In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Cutibacterium Positive Cultures in Total Hip Arthroplasty: Contaminant or Pathogen?

BACKGROUND: Cutibacterium spp. is an emerging pathogen in total hip arthroplasty (THA) that is not well evaluated in the literature. This study reported on the presentation and management of THA complicated by positive intraoperative Cutibacterium cultures. METHODS: This is a retrospective review of 27 revision THAs with positive monomicrobial intraoperative Cutibacterium cultures from 2014 to 2020 at one academic center. These patients were divided into two cohorts based on meeting Musculoskeletal Infection Society (MSIS) criteria for prosthetic joint infections (PJI). Patient demographics, preoperative labs, and hip aspirate results were collected. Procedure performed, postoperative antibiotic regimens, and repeat infections were recorded. Data were compared with univariate analysis. RESULTS: Nine of the 27 patients preoperatively met MSIS criteria for PJI. Patients with positive MSIS criteria had significantly higher median synovial cell count (P = .048) and neutrophil percentage in a preoperative aspirate (P = .050). Eight patients with positive MSIS criteria received six weeks of postoperative antibiotics compared to two patients with negative criteria. Two patients with positive MSIS criteria had a postoperative infection that required further surgical intervention. Four patients with negative criteria who required further surgical intervention did not receive postoperative antibiotics after initial revision. CONCLUSION: While often categorized as a contaminant, Cutibacterium is an increasingly recognized pathogen in THA. Cutibacterium can often present with normal serology, which may result in misdiagnosis as aseptic THA failure. Without the administration of postoperative antibiotics after positive cultures, there is a risk for persistent infection requiring further surgical intervention.

Racial and Ethnic Disparities in the Imaging Workup and Treatment of Knee and Hip Osteoarthritis.

BACKGROUND: There is limited evidence on sociodemographic differences in osteoarthritis management, particularly in non-African American (AA) minorities. We sought to identify differences in imaging modalities, administration of intra-articular injections, and total joint arthroplasty (TJA) between racial/ethnic groups. METHODS: We retrospectively reviewed patients presenting to outpatient clinics with a diagnosis of hip or knee osteoarthritis from January 2013 to March 2020 at a tertiary center. Univariate analyses compared differences between groups. Multivariate logistic regression analyses determined sociodemographic predictors of imaging workup and treatment. RESULTS: In total, 105,873 patients were included. There were 74,769 (70.6%) Caucasian, 27,117 (25.6%) AA, 1,878 (1.8%) Hispanic, 1,479 (1.4%) Asian, and 630 (0.6%) Native American patients. Multivariate analyses demonstrated that AAs had decreased odds of undergoing a knee magnetic resonance imaging (odds ratio [OR] 0.77, P < .001) or injection (OR 0.94, P = .006). Asian patients had lower odds of receiving any hip X-ray (OR 0.72, P = .047) or knee injection (OR 0.83, P = .017). AA (total knee arthroplasty [TKA]: OR 0.51, P < .001; total hip arthroplasty [THA]: OR 0.57, P < .001), Hispanic (TKA: OR 0.69, P = .003; THA: OR 0.60, P = .006), and Asian (TKA: OR 0.73, P = .010; THA: OR 0.56, P = .010) patients had lower odds of undergoing TJA compared to Caucasians. We found that higher income quartiles had greater odds of receiving a magnetic resonance imaging and TJA, males had lower odds of receiving injections and greater odds of undergoing TJA, and Medicaid and self-pay patients had lower odds of undergoing TJA (P < .05). CONCLUSION: After adjusting for sociodemographic factors, we found disparities in the imaging, administration of injections, and/or arthroplasty for AA, Asian, and Hispanic patients. Insurance status, income, and gender were also associated with imaging and treatments performed in managing hip and knee osteoarthritis.