Faculty Bibliography

BACKGROUND:As the popularity of unicondylar knee arthroplasty (UKA) and patellofemoral arthroplasty (PFA) have expanded, more patients who have limited arthritis are undergoing partial knee arthroplasty. No studies have evaluated if any regional differences in the United States (U.S.) exist between partial versus total knee arthroplasty (TKA). The purpose of this study was to utilize the American Joint Replacement Registry to evaluate regional differences in UKA, PFA, and TKA. METHODS:The American Joint Replacement Registry was queried for all TKA, PFA, and UKA procedures between 2012 and 2021. Surgical volume was compared between the Midwest (MW), Northeast (NE), South, and West (W) regions. Trends were compared using multivariate logistic regression analyses and least squared mean logistic regression models. RESULTS:Since 2012, there has been a steady increase in the amount of UKAs performed across the U.S., except during the COVID-19 pandemic when numbers decreased. Logistic regression analyses demonstrated a higher likelihood of receiving a UKA compared to TKA in the NE compared to other regions, and higher likelihood of receiving a PFA in the NE and W compared to other regions over the study period. Other factors that increased the likelihood of having a UKA nationally were men, the procedure being performed at a teaching hospital, and having surgery in urban areas. Patients were more likely to have a PFA in the NE compared to the S and MW, and higher odds in the South and W compared to the MW, with rates of PFA consistently lower in the MW compared to other regions. CONCLUSIONS:Patients were more likely to have a UKA in the NE compared to other regions of the country. Patients had higher odds of having a PFA in the NE and W regions relative to the MW. Men had higher odds of having either UKA or PFA than women across the nation.

BACKGROUND:Isolated acetabular component revision is an effective treatment for revision total hip arthroplasty patients who have well-fixed femoral implants. We aimed to evaluate the modes of acetabular failure following primary total hip arthroplasty and to identify factors associated with increased morbidities and postoperative outcomes. METHODS:We conducted a retrospective analysis and identified 318 isolated aseptic acetabular revisions. We separated patients by ≤90 days, 91 days to 2 years, and >2 years for acetabular revisions and compared demographics, reasons for revision, 90-day readmissions, rerevisions, and postrevision infections. Revisions ≤90 days, 91 days to 2 years, and >2 years accounted for 10.7, 19.2, and 70.1% of revisions, respectively. Revisions ≤90 days, 91 days to 2 years, and >2 years had their primary total hip arthroplasty at a mean age of 66, 63, and 55 years (P < .001), respectively. RESULTS:Revisions within 90 days were mainly indicated for dislocation/instability (58.8%) or periprosthetic fracture (23.5%) while revisions over 2 years were indicated for polyethylene wear/osteolysis (37.2%). Patients with revisions past 90 days were more likely to require rerevision compared to patients with revisions within 90 days (P < .001). There were no differences in readmissions (P = .28) or infection rates (P = .37). CONCLUSIONS:Acetabular revisions within 90 days were more commonly indicated for instability and periprosthetic fracture, while those over 2 years were indicated for polyethylene wear. Revisions past 90 days were more likely to require subsequent rerevisions without increased 90-day readmissions or infections. LEVEL III EVIDENCE/METHODS:Retrospective cohort study.

Postoperative stiffness is a challenging problem in the setting of primary total knee arthroplasty. There remains a relatively high prevalence of patients suffering from this condition, and it can lead to unsatisfactory outcomes and need for revision surgery as well as a large financial burden on the health care system. There are a number of factors that predispose patients to developing arthrofibrosis, including patient-specific factors and intraoperative and postoperative considerations. Arthrofibrosis can be treated effectively in the early stages with manipulation under anesthesia with or without lysis of adhesions, however, those who fail to respond to these interventions may require revision surgery, which generally has poorer outcomes when performed for this indication. Current research is focused on understanding the pathologic cascade of arthrofibrosis and novel targeted therapeutics that may decrease stiffness in these patients and improve outcomes.

Intramedullary stems are often required in patients undergoing revision total knee arthroplasty (rTKA) to achieve stable fixation. Significant bone loss may require the addition of a metal cone to maximize fixation and osteointegration. The purpose of this study was to investigate clinical outcomes in rTKA using different fixation techniques. We conducted a single-institution retrospective review of all patients who received a tibial and femoral stem during rTKA between August 2011 and July 2021. Patients were separated into three cohorts based on fixation construct: press-fit stem with an offset coupler (OS), fully cemented straight (CS) stem, and press-fit straight (PFS) stem. A subanalysis of patients who received tibial cone augmentation was also conducted. A total of 358 patients who underwent rTKA were included in this study, of which 102 (28.5%) had a minimum 2-year follow-up and 25 (7.0%) had a minimum 5-year follow-up. In the primary analysis, 194 patients were included in the OS cohort, 72 in the CS cohort, and 92 in the PFS cohort. When stem type alone was considered, there was no significant difference in rerevision rate (p = 0.431) between cohorts. Subanalysis of patients who received augmentation with a tibial cone demonstrated that OS implants led to significantly higher rates of rerevision compared with the other two stem types (OS: 18.2% vs. CS: 2.1% vs. PFS: 11.1%; p = 0.037). The findings of the present analysis demonstrate that CS and cones in rTKA may provide more reliable long-term outcomes compared with press-fit stems with OS. LEVEL III EVIDENCE:  Retrospective Cohort Study.

Prosthetic joint infection (PJI) remains a major cause of failure in total joint arthroplasty. This complication begets an increase in morbidity and mortality along with significant costs to the healthcare system. The use of prophylactic antibiotics has significant decreased the incidence of this complication. However, the incidence of PJI has not drastically decreased over the last 50 years. This review explores the history, current concepts, and future developments for prevention of PJI prior to incision in total joint arthroplasty.

BACKGROUND/UNASSIGNED:Bicruciate-stabilized (BCS) total knee arthroplasty (TKA) aims to restore normal kinematics by replicating the function of both cruciate ligaments. Conventional cruciate-retaining (CR) design in TKA has shown previous clinical success with lower complication rates. This study compared the patient-reported outcomes between the BCS and CR TKA designs. METHODS/UNASSIGNED:-tests. RESULTS/UNASSIGNED:= 0.028) than the CR cohort (n = 203). Both cohorts displayed a significant difference in delta improvements within their respective cohort when measuring FJS from 3 months to 1 year, 2 years, and 3 years after surgery. CONCLUSIONS/UNASSIGNED:The CR cohort performed better on average, compared to the BCS cohort in measures of KOOS, JR scores at the 2-year follow-up. The BCS cohort performed marginally better regarding FJS only at 1-year follow-up.

BACKGROUND:Large language models (LLM) have unknown implications for medical research. This study assessed whether LLM-generated abstracts are distinguishable from human-written abstracts and to compare their perceived quality. METHODS:The LLM ChatGPT was used to generate 20 arthroplasty abstracts (AI-generated) based on full-text manuscripts, which were compared to originally published abstracts (human-written). Six blinded orthopaedic surgeons rated abstracts on overall quality, communication, and confidence in the authorship source. Authorship-confidence scores were compared to a test value representing complete inability to discern authorship. RESULTS:Modestly increased confidence in human authorship was observed for human-written abstracts compared with AI-generated abstracts (p = 0.028), though AI-generated abstract authorship-confidence scores were statistically consistent with inability to discern authorship (p = 0.999). Overall abstract quality was higher for human-written abstracts (p = 0.019). CONCLUSIONS:AI-generated abstracts' absolute authorship-confidence ratings demonstrated difficulty in discerning authorship but did not achieve the perceived quality of human-written abstracts. Caution is warranted in implementing LLMs into scientific writing.

Introduction: The role of advanced imaging in diagnosing aseptic implant loosening following total hip arthroplasty (THA) remains unclear. This study aimed to assess the diagnostic value of magnetic resonance imaging (MRI) in detecting aseptic loosening. Methods: This was a retrospective review of 342 consecutive patients who underwent revision THA between July 2011 and April 2023 and had a pelvis MRI as part of the preoperative diagnostic evaluation. Among them, 62 patients had an intraoperative diagnosis of aseptic loosening of either the femoral or acetabular component. Patients were stratified based on the concordance between their MRI and radiographs findings. Results: Preoperative MRI showed signs of aseptic loosening in 25/62 patients (sensitivity = 40.3%). Similarly, preoperative radiographs demonstrated signs of aseptic loosening in 27 patients (43.5%). Twelve patients (19.4%) had both MRI and radiographs predictive of aseptic loosening, 22 patients (35.5%) did not show signs of aseptic loosening in either MRI or radiographs, and for 28 patients (45.2%), the results were discordant. Among the patients with a negative radiograph for aseptic loosening (n = 35), 13 patients (37.1%) showed signs of aseptic loosening on MRI. Conclusion: Aseptic loosening remains an elusive diagnosis, and the findings of this study suggest that the utility of MRI and radiographs as part of the diagnostic process is limited. However, in cases of presumed aseptic loosening with inconclusive radiographs findings, MRI may play a role in improving the diagnostic process. Level of evidence: III.

BACKGROUND:In patients who require bilateral total hip arthroplasty (THA) or total knee arthroplasty (TKA), staged procedures are a reasonable option for treatment of bilateral osteoarthritis. We sought to determine whether perioperative outcomes differed between first and second total joint arthroplasty (TJA). METHODS:This was a retrospective review of all patients who underwent staged, bilateral THA or TKA between January 30, 2017, and April 8, 2021. All patients who were included underwent their second procedure within 1 year of the first. Patients were separated based on whether both their procedures took place before or subsequently after an institution-wide opioid-sparing protocol that was implemented on October 1, 2018. A total of 961 patients who underwent 1,922 procedures met the inclusion criteria for this study. For THA, 388 unique patients comprised 776 procedures, while 573 unique patients comprised 1,146 TKAs. Opioid prescriptions were prospectively documented on nursing opioid administration flowsheets and converted to morphine milligram equivalents (MME) for comparison. Activity measure scores for postacute care (AM-PAC) were used as a measurement of physical therapy progression. RESULTS:Hospital stays, home discharges, perioperative opioid usages, pain scores, and AM-PAC scores were not significantly different for the second THA or TKA compared to first procedure, regardless of timing in relation to the opioid-sparing protocol. CONCLUSION/CONCLUSIONS:Patients experienced similar outcomes following their first versus their second TJA. Limited opioid prescriptions following TJA do not negatively impact pain and functional outcomes. These protocols can safely be instituted to help mitigate the opioid epidemic. LEVEL III EVIDENCE/METHODS:Retrospective Cohort Study.

BACKGROUND/UNASSIGNED:Quadriceps weakness following total knee arthroplasty (TKA) delays rehabilitation and increases fall risk. The combined impact of tourniquets and adductor canal blocks (ACBs) on postoperative quadriceps strength has not been defined. This study evaluated the early effects of tourniquet and/or ACB usage on quadriceps strength following TKA. METHODS/UNASSIGNED:Primary, elective TKA patients were assigned to one of four groups based on whether they received an ACB and/or tourniquet. We prospectively measured bilateral, isometric knee extension strength preoperatively and within 36 hours postoperatively. Pre/post-change (Δ) and percent strength change were calculated and standardized to the contralateral leg. Strength, postoperative pain, mobility, knee buckling incidence, and falls were compared across groups. Measurements were collected for 203 patients: 68, 45, 45, and 45 in the tourniquet/ACB, tourniquet/ no ACB, ACB/no tourniquet, and no tourniquet/ no ACB groups, respectively. RESULTS/UNASSIGNED:Tourniquet use was associated with shorter operative time (p=0.004), while ACB use was associated with longer lengths of stay (p=0.005). Average preoperative (p=0.53), postoperative (p=0.12), pre/post-Δ (p=0.60), percent change (p=0.14), and standardized percent change (p=0.85) in strength measures were comparable across groups. Postoperative pain (p=0.67) and knee buckling events (p=0.18) were also comparable across groups. The no tourniquet/no ACB group had decreased postoperative mobility (p=0.004), though it was not clinically significant. No patients sustained inpatient falls. CONCLUSION/UNASSIGNED:.