Faculty Bibliography

BACKGROUND:High body mass index (BMI) is a risk factor for tibial baseplate loosening following total knee arthroplasty (TKA) but may not adequately correlate with stresses at the tibial baseplate. In this study, we aimed to determine an optimal cutoff of a weight-to-tibial baseplate surface-area ratio (weight/SA) for predicting aseptic tibial baseplate loosening. We further examined whether tibial stem extensions have a protective effect. METHODS:We identified 16,368 patients who underwent primary, elective TKA from June 2011 to March 2023. Patient demographics, including age, sex, and race, implants used, and revision surgeries were extracted. Revisions were manually reviewed to confirm revision indications. The exact surface areas of tibial baseplates were obtained from manufacturers. Receiver operating characteristic (ROC) analysis of patients without tibial stem extensions was utilized to examine the utility of BMI and weight/SA for predicting aseptic tibial baseplate loosening. Optimal weight/SA and BMI cutoffs for predicting loosening were determined. The effect of tibial stem extensions on loosening was then examined in patients at or above (n = 7,698; 3.7% with stem extension) and below (n = 8,670; 1.3% with stem extension) the determined weight/SA cutoff. RESULTS:There were 16,368 patients in the final sample (median age, 67 years; 68.9% female; 54.1% White). Weight/SA (area under the curve [AUC] = 0.653; p < 0.001) was a better predictor of aseptic tibial baseplate loosening requiring revision compared with patient BMI (AUC = 0.624; p < 0.001). The optimal weight/SA cutoff for predicting loosening was 0.0162 kg/mm2 (sensitivity = 0.747, specificity = 0.537). Multivariable logistic regression demonstrated that being at or above the weight/SA cutoff (odds ratio [OR] = 3.17; p < 0.001) but not the BMI cutoff (p = 0.911) was a significant predictor of revision for tibial baseplate loosening in patients without stem extensions. No cases of revision for aseptic tibial baseplate loosening in patients with stem extensions occurred either at or above or below the cutoff. The rate of revision for aseptic tibial baseplate loosening in patients without stem extensions was 0.3% for patients below and 1.0% for patients at or above the weight/SA cutoff. CONCLUSIONS:The ratio of weight-to-tibial baseplate surface area was more predictive of revision for aseptic tibial baseplate loosening following TKA compared with BMI alone. For patients with obesity with small tibial baseplate sizes, utilization of a tibial stem extension may protect against tibial loosening. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:A tourniquet is commonly used during total knee arthroplasty (TKA) to improve surgical field visibility and minimize blood loss. While the short-term effects of tourniquet use on postoperative outcomes have been studied extensively and found to be minimal, its influence on longer-term outcomes remains underexplored. This study examined tourniquet use in TKA with up to five-year follow-up. METHODS:In this post hoc analysis of a randomized controlled trial, 227 patients who underwent primary TKA in the tourniquet (T) group (n = 112) or no tourniquet (NT) group (n = 115) were evaluated. Clinical outcomes and patient-reported outcome measures (PROMs) were compared between the two groups. RESULTS:The T group had non-significant trends toward reduced blood loss (131.8 versus 116.7 ml, P = 0.098) and shorter operative time (97.8 versus 95.7 minutes, P = 0.264), with slightly higher postoperative day-one Visual Analog Scale (VAS) pain scores (3.1 versus 3.6, P = 0.197). Length of stay (2.0 versus 2.1 days, P = 0.837) and home discharge rate (88.7 versus 92.0%, P = 0.340) were comparable. The NT group had three 90-day readmissions, while none occurred in the T group (2.7 versus 0%, P = 0.081). The active range of motion at the final follow-up was similar between groups (108.3 versus 106.5 degrees, P = 0.457). All-cause revision rates at five years were comparable between the NT and T groups (5.2 versus 3.6%, P = 0.546). Kaplan-Meier survivorship analysis revealed comparable aseptic implant survival at five years (P = 0.769). There were no significant differences in Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity, PROMIS pain interference, or PROMIS physical health scores at three months, one year, and five years postoperatively. CONCLUSION/CONCLUSIONS:Using a tourniquet during primary TKA was not associated with differences in clinical or patient-reported outcomes at up to five-year follow-up. These findings suggest that tourniquet use in TKA can be left to the surgeon's discretion.

BACKGROUND:Tranexamic acid (TXA) is a renally-excreted antifibrinolytic commonly utilized in total joint arthroplasty (TJA). This study examined whether TXA administration affected clinical outcomes and kidney function in patients who had end-stage renal disease (ESRD) undergoing TJA or hemiarthroplasty. METHODS:Through a retrospective chart review, we identified 123 patients: 40 who underwent primary elective total knee arthroplasty (TKA; 65% received TXA), 34 who underwent primary elective total hip arthroplasty (THA; 52.9% TXA), and 49 who underwent nonelective THA or hemiarthroplasty (44.9% TXA) from January 2011 to February 2024. All patients had ESRD and/or were on dialysis, with no difference in percentage on dialysis between TXA groups (TKA: 65.4 versus 64.3%; THA: 55.6 versus 50.0%; nonelective/hemiarthroplasty: 86.4 versus 85.2%, P values ≥ 0.586). Demographic and perioperative characteristics, including preoperative hemoglobin, TXA administration, dose, and route of administration (ROA; intravenous, topical), were extracted. Pre- and postoperative (≤ 7 days) creatinine, perioperative transfusions, revisions, and 90-day emergency department (ED) visits, readmissions, and mortalities were recorded and compared between TXA groups. RESULTS:In the total sample and all cohorts, change in pre- to postoperative creatinine and incidence of postoperative acute kidney injury (AKI), per Kidney Disease Improving Global Outcomes (KDIGO) guidelines, did not significantly differ based on receiving TXA (P values ≥ 0.159). Among patients receiving TXA, change in creatinine did not significantly differ by dose (P values ≥ 0.428) or ROA (P values ≥ 0.256). There were no statistically significant differences in 90-day ED visits, readmissions, or mortalities based on receiving TXA (P values ≥ 0.055). Thromboembolic events occurred in four patients (one TXA, three no TXA, P = 0.617), and perioperative transfusions occurred in two patients (one TXA, one no TXA, P = 0.882) in the nonelective/hemiarthroplasty cohort, with none in the elective cohorts. CONCLUSIONS:The administration of TXA does not portend a significant increase in complications for patients who have ESRD undergoing TJA or hemiarthroplasty for fracture, suggesting TXA should not be contraindicated in this population.

INTRODUCTION/UNASSIGNED:Previous studies have demonstrated the use of technology in total hip arthroplasty (THA) provided favorable outcomes. This study sought to describe the effect preoperative two-dimensional low-dose (2DLD) full-body radiographs had on the prevention of adverse outcomes following THA. METHODS/UNASSIGNED:We reviewed 11,814 cases of patients who underwent primary, elective THA from 2016 to 2021. Patient demographics and clinical data were compared between patients who did or did not have preoperative standing and sitting 2DLD images (29.5% vs. 70.5%, respectively) using Chi-squared test and multivariate logistic regressions. RESULTS/UNASSIGNED: < 0.001). Multivariate analysis demonstrated preoperative 2DLD images to be significantly associated with lower odds of dislocation, independent from surgical approach, coexisting spinal fusion, and utilization of dual-mobility implants. CONCLUSION/UNASSIGNED:Preoperative 2DLD images were independently associated with decreased risk for dislocations. Even in a higher risk cohort with spinal fusion, the rate of dislocation in the 2DLD cohort was significantly lower.

BACKGROUND:Advances in implant material and design have allowed for improvements in total knee arthroplasty (TKA) outcomes. A cruciate retaining (CR) TKA provides the least constraint of TKA designs by preserving the native posterior cruciate ligament. Limited research exists that has examined clinical outcomes or patient reported outcome measures (PROMs) of a large cohort of patients undergoing a CR TKA utilizing a kinematically designed implant. It was hypothesized that the studied CR Knee System would demonstrate favorable outcomes and a clinically significant improvement in pain and functional scores. AIM/OBJECTIVE:To assess both short-term and mid-term clinical outcomes and PROMs of a novel CR TKA design. METHODS:-tests. RESULTS:Of the 255 patients, 65.5% were female, 43.8% were White, and patients had an average age of 60.6 years. Primary osteoarthritis (96.9%) was the most common primary diagnosis. The mean surgical time was 105.3 minutes and mean length of stay was 2.1 d with most patients discharged home (92.5%). There were 18 emergency department (ED) visits within 90 d of surgery resulting in a 90 d ED visit rate of 7.1%, including a 2.4% orthopedic-related ED visit rate and a 4.7% non-orthopedic-related ED visit rate. There were three (1.2%) hospital readmissions within 90 d postoperatively. With a mean time to latest follow-up of 3.3 years, four patients (1.6%) required revision, two for arthrofibrosis, one for aseptic femoral loosening, and one for peri-prosthetic joint infection. There were significant improvements in KOOS JR, PROMIS Pain Intensity, PROMIS Pain Interference, PROMIS Mobility, and PROMIS Physical Health from preoperative scores to six month and two-year postoperative scores. CONCLUSION/CONCLUSIONS:The evaluated implant is an effective, novel design offering excellent outcomes and low complication rates. At a mean follow up of 3.3 years, four patients required revisions, three aseptic and one septic, resulting in an overall implant survival rate of 98.4% and an aseptic survival rate of 98.8%. The results of our study demonstrate the utility of this kinematically designed implant in the setting of primary TKA.

BACKGROUND/UNASSIGNED:The utilization of technology, including robotics and computer navigation, in total hip arthroplasty (THA) has been steadily increasing; however, conflicting data exists regarding its effect on short-term clinical and patient-reported outcomes. Therefore, this study sought to explore the association between different surgical technologies and postoperative outcomes following THA. METHODS/UNASSIGNED:We retrospectively reviewed 9892 primary THA cases performed by 62 surgeons from a single institution from September 2017 to November 2022. Three cohorts were created based on the utilization of technology: conventional (no technology), navigation, or robotics. Patient demographics, clinical outcomes, and patient-reported outcome measures were collected over the first 90 days following surgery. This data was compared using analysis of variance and multivariate logistic regressions. In total, 4275 conventional, 4510 navigation, and 1107 robotic cases were included in our analyses. RESULTS/UNASSIGNED:< .001) compared to no technology use in THA. Hip dysfunction and Osteoarthritis Outcome Score, Joint Replacement and Patient-Reported Outcomes Measurement Information System Pain Interference scores showed the greatest improvement in the robotic cohort at both 6 weeks and 3 months following surgery. CONCLUSIONS/UNASSIGNED:The present study demonstrates favorable clinical and patient-reported outcomes in the first 90 days following surgery for patients undergoing robot-assisted THA compared to conventional and navigation-assisted THA.

Image-based robotic-assisted total knee arthroplasty (RA-TKA) allows three-dimensional surgical planning informed by osseous anatomy, with intraoperative adjustment based on a dynamic assessment of ligament laxity and gap balance. The aim of this study was to identify ranges of implant alignment and bone resections with RA-TKA. We retrospectively reviewed 484 primary RA-TKA cases, stratified by preoperative coronal alignment. Demographics and intraoperative data were collected and compared using Chi-square and ANOVA tests. Planned limb, femoral, and tibial alignment became increasingly varus in a progressive order from valgus to neutral to the highest in varus knees (p < 0.001). Planned external transverse rotation relative to the TEA was lowest in the valgus cohort; relative to the PCA, whereas the varus cohort was highest (p < 0.001, both). Planned resections of the lateral distal femur and of the medial posterior femur were greater in the varus group compared to neutral and valgus (p < 0.001). There were significant differences between cohorts in planned tibia resections, laterally and medially. Varus knees demonstrated higher variability, while valgus and neutral had more metrics with low variability. This study demonstrated trends in intraoperative planned alignment and resection metrics across various preoperative coronal knee alignments. These findings contribute to the understanding of RA-TKA and may inform surgical decision-making.

INTRODUCTION/BACKGROUND:Literature examining the risks, benefits, and potential complications of TKA in morbidly obese patients is conflicting. Surgeons with more experience performing TKA on morbidly obese patients may generate superior outcomes. This study sought to assess whether complication rates and implant survivorship in morbidly obese TKA patients varies between high (HV) and low (LV) volume surgeons. METHODS:A retrospective review was performed to include all morbidly obese (BMI ≥ 40) patients that underwent primary TKA between January 2016 and July 2021 at our high-volume center. Demographics and clinical outcomes were collected and compared between surgeons with a higher morbidly obese TKA volume (> 10 annual cases) and surgeons with a lower morbidly obese TKA volume. RESULTS:A total of 964 patients (HV 91 [9.4%], LV 873 [90.6%]) were identified. The HV surgeon and LV surgeons had an average annual volume of 15.3 and 5.2 cases, respectively. The average BMI for the HV and LV cohorts were 44.5 ± 3.7 and 44.0 ± 3.6, respectively (p = 0.160). The HV surgeon had significantly lower operative times (105.7 ± 17.4 vs. 110.7 ± 29.6 min, p = 0.018), and a lower 90-day minor complication rate (0.0% vs. 4.7%, p = 0.035). For patients with at least 2-year follow-up, all-cause revision (3.4% vs. 12.5%, p = 0.149) and revision due to PJI (0.0% vs. 5.8%, 0.193) rates were numerically lower in the HV cohort. Improvements in KOOS, JR and VR-12 scores were similar at 3-month and 1-year follow-up. Freedom from all-cause revision (HV: 96.6% vs. LV: 80.4%, p = 0.175) and revision due to PJI (HV: 100.0% vs. LV: 93.6%, p = 0.190, p = 0.190) at latest follow-up did not statistically differ between groups. CONCLUSION/CONCLUSIONS:The HV surgeon had significantly lower operative time and 90-day minor complication rates and numerically lower all-cause revision and revision due to PJI rates when performing TKA in morbidly obese patients. Surgeon's experience may affect surgical outcomes after TKA in morbidly obese patients. LEVEL OF EVIDENCE/METHODS:III.

INTRODUCTION/UNASSIGNED:Total hip arthroplasty (THA) using computer-assisted navigation (N-THA) and robot-assisted surgery (RA-THA) has been increasingly adopted to improve implant positioning and offset/leg-length restoration. Whether clinically meaningful differences in patient-reported outcomes (PROMs) compared to conventional THA (C-THA) are achieved with intraoperative technology has not been established. This systematic review aimed to assess whether published relative PROM improvements with technology use in THA achieved minimal clinically important differences (MCIDs). METHODS/UNASSIGNED: 2786) studies, respectively, for analyses. RESULTS/UNASSIGNED:Statistically significant improvements in postoperative PROM scores were reported in 2/6 (33.3%) studies comparing N-THA with C-THA, though only 1 (16.7%) reported clinically significant relative improvements. Statistically significant improvements in postoperative PROMs were reported in 6/10 (60.0%) studies comparing RA-THA and C-THA, though none reported clinically significant relative improvements. Improved radiographic outcomes for N-THA and RA-THA were reported in 83.3% and 70.0% of studies, respectively. Only 1 study reported a significant improvement in revision rates with RA-THA as compared to C-THA. CONCLUSIONS/UNASSIGNED:Reported PROM scores in studies comparing N-THA or RA-THA to C-THA often do not achieve clinically significant relative improvements. Future studies reporting PROMs should be interpreted in the context of validated MCID values to accurately establish the clinical impact of intraoperative technology.

Periprosthetic joint infections (PJIs) are a devastating complication of joint arthroplasty surgeries that are often complicated by biofilm formation. The development of biofilms makes PJI treatment challenging as they create a barrier against antibiotics and host immune responses. This review article provides an overview of the current understanding of biofilm formation, factors that contribute to their production, and the most common organisms involved in this process. This article focuses on the identification of biofilms, as well as current methodologies and emerging therapies in the management of biofilms in PJI.