Faculty Bibliography

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: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:Discharge disposition after total joint arthroplasty may be predictable. Previous literature has attempted to improve upon models such as the Risk Assessment and Prediction Tool (RAPT) in an effort to optimize postoperative planning. The purpose of this study was to determine whether preoperative laboratory values and other previously unstudied demographic factors could improve the predictive accuracy of the RAPT. METHODS:All patients included had RAPT scores in addition to the following preoperative laboratory values: red blood cell count, albumin, and vitamin D. All values were recorded within 90 days of surgery. Demographic variables including marital status, American Society of Anesthesiologists (ASA) scores, body mass index, Charlson Comorbidity Index, and depression were also evaluated. Binary logistic regression was used to determine the significance of each factor in association with discharge disposition. RESULTS:Univariate logistic regression found significant associations between discharge disposition and all original RAPT factors as well as nonmarried patients (P < 0.001), ASA class 3 to 4 (P < 0.001), body mass index >30 kg/m2 (P = 0.065), red blood cell count <4 million/mm3 (P < 0.001), albumin <3.5 g/dL (P < 0.001), Charlson Comorbidity Index (P < 0.001), and a history of depression (P < 0.001). All notable univariate models were used to create a multivariate model with an overall predictive accuracy of 90.1%. CONCLUSIONS:The addition of preoperative laboratory values and additional demographic data to the RAPT may improve its PA. Orthopaedic surgeons could benefit from incorporating these values as part of their discharge planning in THA. Machine learning may be able to identify other factors to make the model even more predictive.

BACKGROUND:Postoperative return to recreational activity is a common concern among the increasingly active total knee arthroplasty (TKA) patient population, though there is a paucity of research characterizing sport-specific return and function. This study aimed to assess participation level, postoperative return to activity, sport function, and limitations for recreational athletes undergoing TKA. METHODS:A survey of recreational sports participation among primary, elective TKA patients from a single academic center between June 2011 and January 2022 was conducted. Of the 10,777 surveys administered, responses were received from 1,063 (9.9%) patients, among whom 784 indicated being active in cycling (273 [34.8%]), running (33 [4.2%]), jogging (68 [8.7%]), swimming (228 [29.1%]), tennis (63 [8.0%]), skiing (55 [7.0%]), or high-impact team sports (64 [8.2%]) between two years preoperatively and time of survey administration, and were included for analyses. RESULTS:Cycling (62.3% at two years preoperatively vs. 59.0% at latest follow-up) and swimming (62.7% at two years preoperatively vs. 63.6% at latest follow-up) demonstrated the most favorable participation rate changes, while running (84.0% at two years preoperatively vs. 48.5% at latest follow-up) and skiing (72.7% at two years preoperatively vs. 45.5% at latest follow-up) demonstrated the least favorable participation rate changes. The majority of respondents were "satisfied" or "very satisfied" with their return across all sports, though dissatisfaction was highest among runners and joggers. For cycling, running, jogging, and swimming, respondents most commonly reported no change in speed or distance capacity, though among these cyclists reported the highest rates of improved speed and distance. The majority of returning skiers reported improved balance, form, and ability to put on skis. CONCLUSION/CONCLUSIONS:Return to sport is feasible following TKA with high satisfaction. Swimming and cycling represent manageable postoperative activities with high return-rates, while runners and joggers face increased difficulty returning to equal or better activity levels. Patients should receive individualized, sports-specific counseling regarding their expected postoperative course based on their goals of treatment.

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.

BACKGROUND:Utilization of total knee arthroplasty (TKA) continues to rise among patients who have a high comorbidity burden (HCB). With changes in reimbursement models over the past decade, it is essential to assess the financial impact of HCB TKA on healthcare systems. This study aimed to examine trends in revenue and costs associated with TKA in HCB patients over time. METHODS:Of 14,978 TKA performed at a large, urban academic medical center between 2013 and 2021, we retrospectively analyzed HCB patients (Charlson comorbidity index ≥ 5 and American Society of Anesthesiology scores of 3 or 4). A total of 1,156 HCB TKA patients who had complete financial data were identified. Patient demographics, perioperative data, revenue, costs, and contribution margin were collected for each patient. Changes in these financial values over time, as a percentage of 2013 values, were analyzed. Linear regression was performed with a trend analysis to determine significance. RESULTS:From 2013 to 2021, the percentage of HCB TKAs per year increased from 4.2% in 2013 to 16.5% in 2021 (P < .001). The revenue of TKA in HCB patients remained steady (P = .093), while direct costs increased significantly (32.0%; P = .015), resulting in a decline of contribution margin to a low of 82.3% of 2013 margins. There was no significant change in rates of 90-day complications or home discharge following HCB TKA during the study period. CONCLUSIONS:The results of this study indicate a major rise in cost for TKA among HCB patients, without a corresponding rise in revenue. As more patients who have HCB become candidates for TKA, the negative financial impact on institutions should be considered, as payments to institutions do not adequately reflect patient complexity. A re-evaluation of institutional payments for medically complex TKA patients is warranted to maintain patient access among at-need populations.

BACKGROUND:As worldwide utilization of total knee arthroplasty (TKA) broadens, demographic trends can help make projections to inform access to care. This study aimed to assess the temporal trends in the socioeconomic and medical demographics of patients undergoing TKA. METHODS:A retrospective review of 15,848 patients who underwent primary, elective TKA at an urban, New York City-based academic medical center between January 2013 and September 2022 was performed. Trends in patients' age, body mass index (BMI), socioeconomic status (SES) (based on median income by patients' ZIP code), race, and Charlson comorbidity index were evaluated using the Mann-Kendall test. RESULTS:In the last decade, mean patient age (65 to 68 years, P < .001) and Charlson comorbidity index (1.4 to 2.3, P < .001) increased significantly. The proportion of patients who had a BMI ≥ 30 and < 40 increased (43.8 to 51.2%, P = .002), while the proportion of patients who had a BMI ≥ 40 (13.7 to 12.1%, P = .015) and BMI < 30 (42.5 to 36.8%, P = .020) decreased. The distribution of patients' race and SES did not change from 2013 to 2022; Black (18.1 to 16.8%, P = .211) and low SES (12.9 to 11.3%, P = .283) patients consistently represented a minority of TKA patients. CONCLUSIONS:Over the last decade, the average age and comorbidity burden of TKA patients at our institution have increased. This portends the need for higher levels of preoperative optimization and postoperative management for TKA patients. A decreased prevalence of BMI ≥40 could reflect optimization efforts. However, the consistently low prevalence of Black and low-SES patients suggests that recent payment models did not improve access to care for these populations. LEVEL OF EVIDENCE/METHODS:IV.