Faculty Bibliography

INTRODUCTION/BACKGROUND:To our knowledge, outcomes of patients undergoing staged, bilateral total hip arthroplasty (THA) via dissimilar surgical approaches have not yet been investigated. This study examined demographics, implant selection, technology utilization, and component positioning between hips in patients who underwent one THA via posterior and one via direct anterior approach and secondarily evaluated patient-reported outcomes. METHODS:There were 36 patients (72 hips) who underwent staged, bilateral, primary, elective THAs via different approaches from January 2012 to December 2023. Patient demographics, intraoperative technology utilization, implants used, and pre- and postoperative Hip Dysfunction and Osteoarthritis Outcome Scores for Joint Replacement (HOOS-JR) scores were recorded. The hip center of rotation, acetabular height and anteversion, and metaphyseal canal fill were measured on postoperative radiographs. Femoral stem coronal and sagittal plane angulation following both approaches were also compared on postoperative radiographs. RESULTS:There were 15 (41.7%) patients who underwent posterior THA first. The mean time between operations was five years (range, 0.93 to 10.2). Intraoperative technology utilization was more common for the anterior THA (P = 0.002). There were no significant differences in hip center of rotation (P = 0.292), acetabular anteversion (P = 0.428), or acetabular height (P = 0.935) between patients' anterior and posterior approach THAs. The proportion of patients who had posterior stem angulation was significantly greater following anterior THA; neutral stem angulation was seen more frequently following posterior THA (P = 0.005). Lipped liners (P < 0.001), high offset femoral stems (P = 0.007), and dual or triple-taper stems (P < 0.001) were more commonly utilized in posterior THAs. For patients who had pre- and postoperative HOOS-JR for each hip, there was no significant difference in postoperative score improvement between anterior and posterior THAs (P = 0.697), with a mean follow-up time of 2.4 years (range, 0.3 to 9.28) for posterior and 6.1 years (range, 2.8 to 10.3) for anterior THAs (P = 0.249). CONCLUSIONS:Patients undergoing staged, bilateral THAs via different surgical approaches exhibit radiographic characteristics likely attributable to technical challenges for each approach. However, these differences related to approach do not seem to impact short-term clinical and patient-reported outcomes.

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.

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:Recent literature suggests a trend toward a higher comorbidity burden in patients undergoing total knee arthroplasty (TKA). However, the impact of increased comorbidities on the cost-effectiveness of TKA is underexplored. This study aimed to compare the financial implications and perioperative outcomes of patients with and without a high comorbidity burden (HCB). METHODS:We retrospectively reviewed 10,647 patients who underwent elective, unilateral TKA between 2012 and 2021 at a single academic health center with available financial data. Patients were stratified into HCB (Charlson Comorbidity Index ≥ 5 and American Society of Anesthesiology scores of 3 or 4) and non-HCB groups. A 1:1 propensity match was performed based on baseline characteristics, resulting in 1,536 matched patients (768 per group). Revenue, costs, and contribution margins (CM) of the inpatient episode were compared between groups. Ninety-day readmissions and revisions were also analyzed. RESULTS:The HCB patients had significantly higher total (P < 0.001) and direct (P < 0.001) costs, while hospital revenue did not differ between cohorts (P = 0.638). This disparity resulted in a significantly decreased CM for the HCB group (P = 0.009). Additionally, HCB patients had a longer length of stay (P < 0.001) and a higher rate of 90-day readmissions (P = 0.005). CONCLUSIONS:Increased inpatient costs for HCB patients undergoing TKA were not offset by proportional revenue, leading to a decreased CM. Furthermore, higher 90-day readmissions exacerbate the financial burden. These findings highlight potential challenges for hospitals in covering indirect expenses, which could jeopardize accessibility to care for HCB patients. Reimbursement models should be revised to better account for the increased financial burden associated with managing HCB patients. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND:Obesity and diabetes mellitus (DM) pose challenges for patients undergoing total knee arthroplasty (TKA). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as agents for weight and DM management, but they affect multiple organ systems. Outcomes, trends, and demographics for perioperative GLP-1RA use in patients with TKA are not well understood. METHODS:A retrospective review of 13,751 primary, elective TKAs with at least 90 days of follow-up at an urban academic health system between 2012 and 2023 identified 865 patients who had perioperative GLP-1RA use. A 10:1 propensity score match based on sex, age, smoking status, American Society of Anesthesiologists classification, and body mass index created a control cohort of 8,650 TKAs with no GLP-1RA use. RESULTS:The use of GLP-1RAs varied significantly by race, Medicaid insurance, Charlson Comorbidity Index, and presence of DM. Black and Latino patients and those covered by Medicaid were significantly less likely to receive GLP-1RAs. The GLP-1RA group had significantly shorter length of stay (2.1 versus 2.5 days, P < 0.001) and a higher rate of home discharge (91.7 versus 84.2%, P < 0.001). The GLP-1RA users had significantly higher rates of 90-day emergency department visits (5.9 versus 4.0%, P = 0.008), but no differences in 90-day readmissions (4.3 versus 3.6%, P = 0.168) or 2-year revision (2.3 versus 2.6%, P = 0.362) compared to matched controls. The GLP-1RA patients had significantly lower all-cause revision rates at the last follow-up (2.7 versus 3.9%, P = 0.034), but there was no significant difference in Kaplan-Meier implant survival (P = 0.311). Before TKA, GLP-1RA patients had an average decrease in body mass index of 0.4, compared to an average increase of 1.2 for matched controls. CONCLUSIONS:Our results demonstrate that the use of GLP-1RAs is significantly lower for minority patients and those covered by Medicaid. Patients using GLP-1RAs have noninferior clinical outcomes with the potential for weight loss leading up to TKA. LEVEL OF EVIDENCE/METHODS:III.

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:The relationship between total hip arthroplasty (THA) surgeon volume and outcomes is informative in this era of health care value optimisation. The purpose of this study was to evaluate outcomes based on modern-day surgeon practice volumes. METHODS:The SPARCS database was queried for patients undergoing primary THA from 2010 to 2020. Annual case volume thresholds were 30 and 150, differentiating high-volume (HV), intermediate-volume (IV), and low-volume (LV) groups. Perioperative outcomes and all-cause cumulative revision rates were evaluated. RESULTS: 0.001). While controlling for confounders, multivariate regression revealed increased odds of PJI for IV (1.5) and LV (1.87) and increased all-cause revision hazard ratio for IV (1.1) and LV (1.3). Cumulative revision rates were lower for HV at 1 and 2 years, but rates converged with IV group at 9 years. CONCLUSIONS:HV surgeons have the most favourable short-term outcomes. However, in the long-term the difference in all-cause revision event rates becomes less apparent.

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.

BACKGROUND:Annotating free-text clinical notes into structured data is critical for future large-scale data analysis in institutional and national orthopaedic registries. In total hip arthroplasty (THA), classifying implant fixation, use of technology, and especially surgical approach are particularly difficult for classical machine-learning techniques. In this pilot, we evaluated the feasibility of GPT-4 to capture and justify these common elements in THA operative notes using a custom few-shot learning prompt. METHODS:The GPT-4 was trained with a few-shot learning approach using plain language descriptions of various fixations, technologies, and approaches, along with examples from gold-standard operative notes-four for fixation, 11 for technology, and 13 for surgical approach. The test set comprised 240 unique notes (60 for fixation, 90 for technology, and 120 for approach) from primary THAs performed by 38 surgeons at a single institution (November 2011 to March 2024). The GPT-4's output was compared against manual chart reviews for accuracy. The quality of clinical justifications was assessed using Flesch-Kincaid Grade Level (FKGL) scores for readability, self-BLEU scores for logical diversity, and character-level sequence matches with original notes. RESULTS:The GPT-4 classified fixation, technology, and approach with an overall accuracy of 100, 98.9, and 97.5%, respectively. The model also provided justifications for classifications with average FKGL scores of 17.9, 16.2, and 24.4 for fixation, technology, and approach, respectively, and average self-BLEU scores of < 0.1 each. Justifications had character-level sequence matches of 87.6, 89.2, and 96.5%, respectively, with direct note citations for fixation, technology, and approach. CONCLUSION/CONCLUSIONS:Applying GPT-4 with a custom few-shot prompt to THA operative notes demonstrated excellent performance in capturing fixation, technology, and approach methods. Moreover, the model's ability to cite details from the original notes is critical for model validation before widespread adoption, exhibiting a promising alternative to manual chart review for clinical data capture.