Faculty Bibliography

BACKGROUND:10 years after changing our institution's total hip arthroplasty (THA) preoperative antibiotic prophylactic protocol by adding gram-negative (GN) coverage, this study aimed to assess the impact of adding GN specific coverage (GNSC) prior to THA on periprosthetic joint infection (PJI) rates. METHODS:This was a retrospective case-control study of 14,598 patients who underwent primary, elective THA between July 2012 and January 2022, with minimum 1-year follow-up. All patients were under perioperative antibiotic protocol that included GNSC with either weight-based gentamicin or aztreonam (+GNSC) and were compared to a historical control group of patients for which the antibiotic prophylactic protocol did not include GNSC (-GNSC). PJI and nephrotoxicity rates, as well as the severity of nephrotoxicity according to the RIFLE criteria, were compared between the study populations and 4122 controls. RESULTS: = 0.567), which are the two more severe forms of nephrotoxicity, were comparable between the groups. CONCLUSIONS:The addition of gentamicin or aztreonam prior to THA reduces the incidence of GN-related PJIs. Increased nephrotoxicity rates were limited to the mildest form, usually associated with reversibility and favourable outcomes.

BACKGROUND:Patients often desire to participate in sports following total hip arthroplasty (THA) and total knee arthroplasty (TKA), but may be limited functionally and also socioeconomically. The purpose of this study is to investigate the sports participation rates in total joint arthroplasty (TJA) patients based on their Distressed Communities Index (DCI). METHODS:Patients who underwent TJA at our institution from 2015 to 2020 were surveyed on sports/physical activity participation before and after TJA. In total, 2,335 patients were surveyed: 780 (33.4%) underwent THA, 1,158 (49.6%) underwent TKA, and 397 (17.0%) underwent both THA and TKA. Patients were grouped based on their DCI score into either the prosperous (N = 1,126), comfortable (N = 634), or mid-tier/at-risk/distressed (N = 575) groups. Data was correlated with demographic and outcome scores. RESULTS:Participation rates were 85.3, 84.2, and 77.7% at five years before TJA in the prosperous, comfortable, and mid-tier/at-risk/distressed groups, respectively (P < 0.001). Participation rates were 74.2, 70.7, and 66.6%, at a mean of 4.0 years postoperatively (P = 0.004). For all three groups, the most popular sports were recreational walking, swimming, cycling, and golf, and there were significantly lower preoperative and postoperative levels of participation in these physical activities in the more distressed groups. Multivariate logistic regression showed that a DCI of 3 or higher significantly predicted the ability to participate in sports (P = 0.012). CONCLUSION/CONCLUSIONS:While sports participation rates are high in most TJA patients, participation is decreased compared to five years preoperatively, transitions to low-impact activities, and patients who are from more distressed communities report lower sports participation rates.

INTRODUCTION/BACKGROUND:Technology is increasingly incorporated into unicompartmental knee arthroplasty (UKA) through computer-assisted navigation (N-UKA) and robot-assisted surgery (R-UKA) to improve alignment, implant positioning, and gap balancing. Whether intraoperative technology helps achieve the minimal clinically important difference (MCID) in patient-reported outcomes (PROMs) compared to conventional UKA (C-UKA) remains unclear. This systematic review aimed to assess whether differences in PROMs between C-UKA and technology-assisted UKA reached MCID values. MATERIALS AND METHODS/METHODS:PubMed/MEDLINE/Cochrane Library were reviewed for studies comparing PROMs between primary C-UKA (control group) and N-UKA or R-UKA. Delta improvements were compared to established MCID values. Additional radiographic and clinical differences were assessed. The review yielded four (N=328) N-UKA and seven (N=526) R-UKA studies with C-UKA cohorts as controls. RESULTS:Differences in preoperative and postoperative PROMs were reported as statistically significant in three of four studies (75%) comparing N-UKA and C-UKA; however, none of the studies reported values that reached the MCID. Differences in preoperative and postoperative PROMs were reported as statistically significant in four of seven studies (57.1%) comparing R-UKA and C-UKA; however, only three of the studies (42.9%) reported values that reached the MCID. Improved radiographic outcomes for N-UKA and R-UKA were reported in 75% and 57.1% of studies, respectively. Only one study reported improved revision rates with R-UKA compared to C-UKA. CONCLUSION/CONCLUSIONS:Though studies may report better improvements in PROMs in N-UKA and R-UKA compared to C-UKA, these often may not achieve clinical significance. Future studies should present outcome differences in the context of validated MCID as well as other metrics such as revision rates and radiographic outliers as the impetus for technology-assisted UKA.

(1) Introduction: Precise femoral component rotation is critical for achieving symmetric flexion-gap balance and physiologic patellofemoral tracking in mechanically aligned total knee arthroplasty (TKA). Surgeons often infer an appropriate rotational target from the patient's coronal limb alignment, yet the strength of this relationship remains uncertain. (2) Methods: We identified 695 consecutive patients undergoing primary TKA with a preoperative planning CT scan. The surgical transepicondylar axis (sTEA) and posterior condylar axis (PCAxis) were identified and the angle between them was measured. The angle between the mechanical axis of the femur and tibia was used to measure the coronal alignment of the limb. (3) Results: The mean sTEA was 3.0° externally rotated to the PCAxis (range 3.1° internal to 9.2° external). The mean coronal alignment was 4.3° varus (range -12.5° valgus to 24.5° varus). There were 465 patients with >2° varus and 101 patients with >2° valgus. The mean sTEA was 2.9 ± 1.9° externally rotated relative to the PCAxis in the valgus group and 2.8 ± 2.0° in the varus group, with no statistically significant difference (p = 0.7). (4) Conclusions: There is significant variation in the femoral rotation axes between patients, but no significant relationship between overall limb coronal alignment and the magnitude of femoral rotation axes variation. This reinforces the need for independent assessment of rotational landmarks when performing mechanically aligned TKA.

BACKGROUND:The cementation technique is crucial for achieving adequate fixation and optimal survivorship in total knee arthroplasty (TKA). The thickness of the cement at the tibial bone-implant surface may be related to aseptic tibial loosening. However, to date, no studies have demonstrated a direct association between cement thickness and rates of aseptic tibial loosening. METHODS:We performed a retrospective review to identify 28,327 primary cemented TKAs with at least 2 years of follow-up at an academic health system from 2013 to 2021. A total of 115 cases underwent revision surgery for aseptic tibial loosening. Cases where the implant was recalled specifically for loosening (n = 23) were excluded. The remaining 92 aseptic tibial loosening cases were 2:1 propensity score matched and implant matched to control patients who did not have tibial loosening. There were two independent reviewers who then measured the thickness of the cement interface in 10 locations along the bone-implant interface from initial postoperative radiographs. The averages of the reviewers' measurements were calculated and then compared using independent t-tests. RESULTS:Aseptic tibial loosening cases involving implant A tibial baseplate (n = 75) had significantly thinner cement interfaces than matched controls at all the 10 locations measured. Aseptic loosening cases involving implant B (n = 17) also displayed a thinner cement interface than matched controls in all locations, but this result was only statistically significant at the medial baseplate, medial keel, lateral keel, anterior keel, and posterior baseplate. CONCLUSIONS:In two widely used TKA systems, tibial aseptic loosening was associated with significantly thinner cement interfaces when compared to propensity-matched controls in two different implant types. Further prospective studies are needed to identify the optimal keel preparation and design as well as minimal cement interface thickness to avoid implant loosening. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND:Despite theoretical risks of fatigue wear, there is little empirical evidence correlating postoperative impact level from physical activity with failure rates following total hip and knee arthroplasty (THA and TKA). This study aimed to assess the relationship between the impact level from self-reported sports and physical activity participation and revision rates following primary arthroplasty. METHODS:A survey was conducted on recreational sports participation among primary elective THA and TKA patients from an urban, academic health system between June 1, 2011, and January 31, 2022. A total of 1,622 THA and 1,388 TKA respondents were included in the study. The survey was administered cross-sectionally at various time points, with a minimum follow-up of at least one year required for inclusion (THA, 5.3 years; TKA, 4.8 years postoperation on average). Patients were divided into four cohorts based on participation and intensity of the sport: no sports, low-impact sports, intermediate-impact sports, and high-impact sports. Descriptive comparisons were made to evaluate revision rates and mean time to follow-up among these groups in THA and TKA patients. The Kaplan-Meier method was utilized to assess 10-year implant survivability. RESULTS:Healthier and younger patients who underwent THA or TKA were significantly more likely to participate in intermediate- to high-impact sports and were found to have noninferior revision rates than those who engaged in no sports or low-impact sports: THA (2.9 [no sports] versus 1.9 [low impact] versus 1.6% [intermediate/high impact]), TKA (3.0 versus 1.6 versus 0.0%). When analyzing aseptic versus septic revisions separately, no notable patterns or differences were observed. CONCLUSIONS:At a mean 5-year follow-up, healthier and younger patients who participated in intermediate- and high-impact physical activities had noninferior revision rates as than patients who were less active. These findings offer guidance for clinicians when advising patients on the safe resumption of sports activities following total joint arthroplasty.

BACKGROUND:Patients' satisfaction and job limitations after primary total hip arthroplasty (THA) based on occupation intensity have not been evaluated. This study aimed to assess patients' ability and satisfaction with their return to work following primary THA depending on intensity of their occupation. METHODS:This retrospective review surveyed patients undergoing primary THA between June 2011 and January 2022, with at least one year of follow-up, on return to work rates. Of 1,713 participants, 1,176 (68.7%) reported working prior to THA and were stratified into high intensity (HI) (i.e. laborer, construction), standard intensity (SI) (i.e. walking, climbing stairs), and low intensity (LI) (i.e. desk jobs) groups. Baseline demographics and survey responses were compared. Among patients who worked preoperatively, 66 (5.6%), 450 (38.3%), and 660 (56.1%) were in the HI, SI, and LI groups, respectively. RESULTS:High rates of workers across all groups reported improvements in their ability to work following THA, with 74.8% of SI, 68.8% of LI workers and 63.6% of HI workers reporting "remarkable" or "modest improvement." The HI group was more likely male, younger, and a current smoker compared to the SI and LI groups. Among LI workers, 47.2% returned within the first month and83.6% returned within two months. SI workers showed a similar pattern, with 36.2% returning in less than a month and 79.7% returning within two months. HI workers had a comparatively lower return rate, with 12.3% returning within the first month and 52.6% returning within two months. CONCLUSION/CONCLUSIONS:Across all intensity levels, THA enables improvements in perceived work function and satisfaction. However, higher-intensity work requires more time, is more difficult, and yields lower return-to-work satisfaction compared to low-intensity work.

INTRODUCTION/BACKGROUND:Maintaining follow-up after total joint arthroplasty (TJA) is critical to monitor patient outcomes and complications. However, patient factors associated with follow-up compliance have not been described previously. This study aimed to characterize demographic and perioperative characteristics associated with TJA follow-up compliance. METHODS:This was a retrospective review of all primary, elective total hip and knee arthroplasty (THA and TKA) procedures at an urban, tertiary care center from 2011 to 2022. Patient follow-ups were categorized as early (0 to 90 days), mid-term (91 days to two years), and late-term (greater than two years). Patient characteristics, including age, sex, race, smoking status, spoken language, body mass index, income class, insurance type, distance from hospital, 90-day readmission, American Society of Anesthesia Status, and Charlson Comorbidity Index (CCI), were compared at each period, and logistic regression identified predictors of follow-up. RESULTS:In total, 2,836 TKA and 3,056 THA procedures were analyzed, with overall follow-up rates of 78.9 and 76.8%, respectively. Among all TJA patients, those who did not have follow-up were more likely to be younger, men, White, active smokers, live further from the hospital, and have lower CCIs. Uniquely, for TKA patients, higher income status predicted lower overall and early follow-up rates, while English-speaking predicted lower early and higher late follow-up rates in this subgroup. Differences between groups based on follow-up status decreased as follow-up time increased. Regression analyses showed loss to follow-up increased with increased distance from the hospital and current smoking. Uniquely, for THA, men predicted loss-to-follow-up. CONCLUSION/CONCLUSIONS:Younger age, men, White race, higher income, current smoking, and increased distance from the hospital are associated with increased early, but not late, loss to follow-up after TJA. Future studies should assess the influence of other factors, including home support and telemedicine use, on follow-up rates.

BACKGROUND:Cementless total knee arthroplasty (TKA) has recently regained popularity, yet data has raised concerns about rates of arthrofibrosis following these procedures. The purpose of this study was to utilize the American Joint Replacement Registry to compare rates of early manipulation under anesthesia (MUA) in cementless and cemented primary TKAs that use technology or manual instrumentation. METHODS:We queried the American Joint Replacement Registry for all patients ages 18 to 95 years who underwent cemented or cementless primary TKA over a 7-year period. Patients were stratified based on whether technology (robotics or computer-assisted navigation) was used during the primary surgery. Groups were then compared for rates of MUA within 90-day of the index surgery using multivariable logistic regression models. A total of 340,841 cases were included in the study, 78,397 (23%) of which used technology and 262,444 (77%) which did not. Within the technology cohort, there were 51,500 (65%) robotic and 26,897 (35%) navigated cases. There were 65% of technology-assisted TKAs and 92% of manual TKAs cemented. RESULTS:In the technology group, multivariable analysis demonstrated significantly higher odds of MUA in cemented TKAs compared to cementless (odds ratio [OR] 1.95, 95% confidence interval [CI] [1.06 to 3.59]; P = 0.031). Robotic cases had significantly higher odds of MUA with cemented compared to cementless implants (OR 2.38, 95% CI [1.27 to 4.46]; P = 0.007), while there was no difference in MUA related to cementation in the navigated cases (OR 3.53, 95% CI [0.48 to 25.95]; P = 0.22). In the manual group, there were no significant differences in MUA rates related to cementation use (OR 1.14, 95% CI [0.8 to 1.64]; P = 0.46). CONCLUSIONS:Cementless TKA did not increase odds of MUA. In further analyzing cement use into technology and manual cohorts, robotic-assisted cemented TKAs had higher rates of early MUA than cementless. Identification of risk factors leading to early arthrofibrosis may be patient dependent and further study is required to elucidate any surgical considerations.

BACKGROUND:Same-day cancellations of elective surgeries present challenges to patients, providers, and healthcare institutions. This study aimed to investigate the frequency and predictors of same-day cancellations for elective total joint arthroplasty (TJA). METHODS:A retrospective review was conducted on 13,744 scheduled primary, elective TJAs at an urban academic center from September 2017 to August 2023. Cases that experienced same-day cancellations were grouped based on the reasoning for cancellation into one of two categories - operative concern (e.g., acute health issues, medication non-compliance) or a nonoperative concern (e.g., financial clearance, transportation issues). Patient demographics were compared between the cancellation and surgery cohorts and between the categorical reasons for cancellation. RESULTS:Out of the 38,849 scheduled TJAs, 362 cases (0.9%) were canceled on the day of surgery. Higher patient body mass index (BMI) was the singular patient factor predictive of same-day cancellation across all TJAs. Non-white race, men, and higher Charlson Comorbidity Index (CCI) were additional significant predictors for THA, but not TKA cancellation. Operative concerns accounted for 74.9% of the cancellations, and nonoperative concerns accounted for 25.1%. Increased patient BMI was predictive of TJAs canceled due to operative concerns, whereas younger patient age was predictive of TJAs canceled due to nonoperative concerns. Of all same-day cancellations, 81.8% were ultimately rescheduled, and rescheduled cases occurred at a median of 25 days (range, one to 425) after cancellation. There were no significant differences in rescheduling rates and time to reschedule cases between the reasons for cancellation. CONCLUSION/CONCLUSIONS:Approximately 1% of patients experienced a same-day cancellation of their elective TJA, most of which occurred due to operative concerns. These findings may guide the development of preoperative optimization strategies aimed at reducing the occurrence of same-day cancellations for high-risk patients, thereby maximizing the utilization of operative resources and enhancing care for TJA patients.