Faculty Bibliography

Background:Dual mobility (DM) bearings for total hip arthroplasty (THA) have been proposed to reduce the risk of instability in high-risk patients; however, their utility in primary THA remains relatively unexplored. No previous reports have described whether surgical approach influences outcomes associated with DM implant systems. This study aims to compare patient reported outcomes and post-operative groin pain between patients undergoing anterior approach versus posterior approach following primary THA with DM implants. Methods:We retrospectively reviewed all patients who underwent primary THA and received a DM implant between 2011-2021. Patients were stratified into two cohorts based on surgical approach (anterior vs. posterior approach). Primary outcomes included the presence of substantial postoperative groin pain as well as readmission and revision rates. Demographic differences were assessed using chi-square and independent sample t-tests. Outcomes were compared using multilinear and logistic regressions. Results:Of the 495 patients identified, 55 (11%) underwent THA via the anterior approach and 440 (89%) via the posterior approach. Surgical time (100.24 vs. 109.42 minutes, p=0.070), length of stay (2.19vs.2.67 days,p=0.072), discharge disposition (p=0.151), and significant postoperative groin pain (1.8%vs.0.7%,p=0.966) did not statistically differ between the cohorts. 90-day readmission (9.1%vs.7.7%,p=0.823) and revision rate (0.0%vs.3.0%,p=0.993) did not significantly differ as well. Specifically, readmission (p=0.993) and revision (p=0.998) for instability did not significantly differ between the cohorts. We found no statistical difference in HOOS, JR (p=0.425), VR-12 PCS (p=0.718), and VR-12 MCS (p=0.257) delta score improvement from preoperative to 1-year follow-up between the two groups. Conclusion:.

INTRODUCTION:Posterior cruciate ligament (PCL) retention may impact a patient's awareness of their artificial joint following primary total knee arthroplasty (pTKA) due to increased proprioception and more native knee kinematics. Therefore, the purpose of this study was to investigate whether cruciate-retaining (CR) or posterior-stabilized (PS) implants influence the Forgotten Joint Score (FJS-12) following pTKA. METHODS:We retrospectively reviewed all patients who underwent pTKA with a CR or PS implant at our institute between October 2017 and March 2021. Of the 6,258 patients identified, 5,587 did not have recorded FJS-12 scores at either three months, one year, or two years postoperatively nor a Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) preoperatively, three months, or one year postoperatively, and these were considered lost to follow up. Thus, a total of 671 cases were identified and subsequently stratified into two cohorts based on whether they received a CR (n=236, 35%) or PS (n=435, 65%) implant. Patients who received PS implants were further divided into constrained (CoN) and non-constrained (NCoN) liner cohorts. Multivariable linear regression analysis was used to compare patient-reported outcome (PRO) scores. RESULTS:There were no significant differences in PRO scores between CR and PS implants at any time point. Patients in the CoN (n=74) cohort had significantly higher FJS-12 scores at one year (CoN: 56.31 + 25.34 vs NCoN: 42.24 + 27.00, p=0.001) and two years (CoN: 58.52 + 33.71 vs NCoN: 46.97 + 27.44, p=0.013) postoperatively compared to patients in the NCoN (n=361) cohort. CONCLUSION:Although our analysis demonstrated significant differences in FJS-12 scores at one and two years postoperatively depending upon the liner constraint, there were no significant differences in FJS-12 scores between CR and PS implants. Therefore, while retention of the PCL does not impact patient awareness of their artificial joint, the level of liner constraint may influence outcomes if the PCL is sacrificed.

INTRODUCTION/BACKGROUND:Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is challenging to diagnose. We aimed to evaluate the impact of dry taps requiring saline lavage during preoperative intraarticular hip aspiration on the accuracy of diagnosing PJI before revision surgery. METHODS:A retrospective review was conducted for THA patients with suspected PJI who received an image-guided hip aspiration from May 2016 to February 2020. Musculoskeletal Infection Society (MSIS) diagnostic criteria for PJI were compared between patients who had dry tap (DT) versus successful tap (ST). Sensitivity and specificity of synovial markers were compared between the DT and ST groups. Concordance between preoperative and intraoperative cultures was determined for the two groups. RESULTS:In total, 335 THA patients met inclusion criteria. A greater proportion of patients in the ST group met MSIS criteria preoperatively (30.2%vs.8.3%, p<0.001). Patients in the ST group had higher rates of revision for PJI (28.4%vs.17.5%, p=0.026) and for any indication (48.4%vs.36.7%, p=0.039). MSIS synovial WBC count thresholds were more sensitive in the ST group (90.0%vs.66.7%). There was no difference in culture concordance (67.9%vs.65.9%,p=0.709), though the DT group had a higher rate of negative preoperative cultures followed by positive intraoperative cultures (85.7%vs.41.1%, p=0.047). CONCLUSION/CONCLUSIONS:Our results indicate that approximately one-third of patients have dry hip aspiration, and in these patients cultures are less predictive of intraoperative findings. This suggests that surgeons considering potential PJI after THA should apply extra scrutiny when interpreting negative results in patients who require saline lavage for hip joint aspiration.

INTRODUCTION/BACKGROUND:Although technology-assisted total hip arthroplasty (TA-THA) may improve implant positioning, it remains unknown whether TA-THA confers improved clinical outcomes. We sought to examine national TA-THA utilization trends and compare clinical outcomes between TA-THA and unassisted THA (U-THA). METHODS:Patients who underwent primary, elective THA from 2010 to 2018 were identified using the American College of Surgeons National Surgical Quality Improvement Program database. Demographic, perioperative, and 30-day outcomes were queried and collected. Patients were stratified based on whether they underwent TA-THA, which included computer navigation or robotics, and U-THA. Propensity score matching paired patients undergoing TA-THA or U-THA on a 1:1 basis. RESULTS:Of the 238,755 THA patients, 3,149 cases (1.3%) were done using TA-THA. Comparing the unmatched TA-THA and U-THA groups, race distribution (P < 0.001) and baseline functional status (P < 0.001) differed. Propensity score matching yielded 2,335 TA-THA and U-THA pairs. Perioperatively, the TA-THA cohort had longer mean surgical times (101.0 ± 34.0 versus 91.9 ± 38.8 minutes, P < 0.001), but lower transfusion rates (5.7% versus 7.8%, P = 0.005). As compared with the U-THA group, the TA-THA group had a shorter mean hospital length of stay (2.0 ± 1.1 versus 2.5 ± 2.0 days, P < 0.001) and a higher proportion of patients discharged home (85.8% versus 75.7%, P < 0.001). Notably, the TA-THA cohort had higher readmission rates (3.8% versus 2.4%, P < 0.001). Major complication and revision surgery rates did not markedly differ between groups. DISCUSSION/CONCLUSIONS:TA-THA utilization rates remain low among orthopaedic surgeons. As compared with U-THA, TA-THA yield mixed perioperative and 30-day outcomes. Surgeons must consider the clinical benefits and drawbacks of TA-THA when determining the proper surgical technique and technology for each patient. Clinical trials assessing long-term functional and clinical outcomes between U-THA and TA-THA are required to further elucidate the utility of assistive technologies in THA. LEVEL III EVIDENCE/UNASSIGNED:Retrospective Cohort Study.

BACKGROUND:While technology-assisted total knee arthroplasty (TA-TKA) improves implant positioning, whether it confers improved clinical outcomes remains inconclusive. We sought to examine national TA-TKA utilization trends and to compare outcomes between TA-TKA and unassisted TKA (U-TKA). METHODS:Patients who underwent primary, elective TKA from 2010 to 2018 were identified using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Demographic, perioperative, and 30-day outcomes were collected. Patients were stratified on the basis of whether they underwent TA-TKA, which included computer navigation and robotics, or U-TKA. The proportion of patients undergoing TKA using TA-TKA was calculated. One-to-one propensity-score matching paired patients undergoing TA-TKA or U-TKA. Independent samples t-tests and Mann-Whitney U tests were used to compare continuous variables, and chi-squared tests were used to compare categorical variables. RESULTS:Of the 402,284 TKA patients, 10,429 (2.6%) cases were performed using TA-TKA. Comparing the unmatched TA-TKA and U-TKA groups, race (p < 0.001), smoking status (p = 0.050), baseline functional status (p < 0.001), and body mass index (BMI) (p < 0.001) significantly differed. Propensity-score matching yielded 8633 TA-TKA and U-TKA pairs. The TA-TKA cohort had shorter hospital length of stay (LOS) (2.7 ± 2.5 versus 2.8 ± 1.9 days, p = 0.017) but similar operative times (92.4 ± 33.4 versus 92.6 ± 39.8 min, p = 0.670). Compared with the U-TKA group, the TA-TKA group had lower major complication (7.6% versus 9.4%, p < 0.001) and transfusion (3.9% versus 5.1%, p < 0.001) rates and higher rates of discharge to home (73.9% versus 70.4%, p < 0.001). Reoperation and readmission rates did not significantly differ between groups. CONCLUSIONS:TA-TKA utilization remains low among orthopedic surgeons. Compared with U-TKA, TA-TKA yielded improved perioperative and 30-day outcomes. Nonetheless, surgeons must consider the benefits and drawbacks of TA-TKA when determining the proper surgical technique and technology for each patient. LEVEL III EVIDENCE/METHODS:Retrospective cohort study.

BACKGROUND:Obesity is a recognized risk factor for severe knee osteoarthritis. However, it remains unclear how obesity prevalence trends in the current population undergoing total knee arthroplasty (TKA) compare with those seen in individuals not undergoing this procedure. In this study, we assessed the yearly trends in body mass index (BMI) and obesity rates between patients who have undergone primary TKA and those in the general population. METHODS:We retrospectively reviewed all patients ≥18 years of age from January 2013 through December 2020 who underwent primary, elective TKA and those who had an annual routine physical examination at our institution within the same period. Baseline demographic characteristics were collected. The independent samples t test was used to compare means and the chi-square test was used to compare proportions between the 2 cohorts, and a linear regression was used to determine the significance of the yearly trends. RESULTS:A total of 11,333 patients who underwent primary TKA and 1,158,168 patients who underwent an annual physical examination were included in this study. After adjusting for age, we found the mean BMI for the TKA group to be significantly greater (p < 0.001) every year compared with the annual physicals group. The proportion of patients who were categorized into any obesity class (BMI, ≥30 kg/m2), Class-I obesity (BMI, 30 to 34.9 kg/m2), Class-II obesity (BMI, 35 to 39.9 kg/m2), and Class-III obesity (BMI, ≥40 kg/m2) was significantly higher for the TKA group each year compared with the annual physicals group. An analysis of trends over time showed a significantly increasing trend (p < 0.001) in BMI and obesity rates for the annual physicals group, but a stable trend for patients undergoing TKA. CONCLUSIONS:Patients who underwent TKA continued to have higher BMI than the general population, which showed a steady increase over time. Physicians need to continue in their efforts to educate patients on weight management and healthy lifestyles to potentially delay the need for a surgical procedure. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

INTRODUCTION/UNASSIGNED:Advanced age is considered a major risk factor for postoperative complications in total hip arthroplasty (THA). Consequently, older patients undergoing THA may require more detailed pre-procedural examinations and more healthcare resources postoperatively than younger patients. The purpose of this study was to compare discharge parameters and complication rates of THA in patients ⩾90 years old to those <90 years old. METHODS/UNASSIGNED:-tests. RESULTS/UNASSIGNED:= 1.000). CONCLUSIONS/UNASSIGNED:Although THA patients over 90 years of age had a longer LOS and differing discharge disposition, these patients had similar complications compared to their younger counterparts. Thus, our study supports similar efficacy of THA in patients 90 years and older relative to younger THA candidates.

Dual mobility designs in total arthroplasty allow for increased range of motion prior to impingement and dislocation. While valuable for reducing dislocation, dual mobility has its own unique complication profile that includes intraprosthetic dislocation, corrosion, and femoral notching. Despite these relatively rare complications, dual mobility articulations are valuable options for patients at higher risk of dislocation-both early and contemporary reports on dual mobility in total hip arthroplasty suggest that it can reduce the risk of dislocation without leading to unacceptable rates of complication or early revision. Cost analyses and longer follow-up studies on newer dual mobility designs will help determine the future of dual mobility in total hip arthroplasty.

BACKGROUND:Image-guided joint aspirations used to assist the diagnosis of periprosthetic joint infection (PJI) may commonly result in a dry tap-or insufficient fluid for culture and cell count analysis. Dry tap aspirations are painful and invasive for patients and often utilize a subsequent saline lavage to obtain a microbiology sample. Currently, there is a paucity of the literature addressing predictors that could suggest whether a dry tap will occur. The purpose of this study was to examine the effects of various factors on "dry tap" occurrence in patients with suspected PJI following total hip arthroplasty (THA). METHODS:A retrospective review was performed among THA patients suspected for PJI who received image-guided joint aspiration procedures at our institution from May 2016 to February 2020. The procedural factors included the imaging modality used for aspiration, anatomic approach, needle gauge size used, and the presence of a trainee. The patient-specific factors included number of prior ipsilateral hip surgeries, femoral head size, ESR/CRP values, and BMI. RESULTS:In total, 336 patients met our inclusion criteria. One hundred and twenty hip aspirations resulted in a dry tap (35.7%) where the patients underwent a saline lavage. Among the procedural and patient-specific factors, none of the factors were found to be statistically different between the two cohorts nor conferred any greater odds of a dry tap occurring. CONCLUSION/CONCLUSIONS:No associations with dry tap occurrence were found among the procedural and patient-specific factors studied. Further research is needed to identify additional factors that may be more predictive of dry taps.