Faculty Bibliography

BACKGROUND:Managing recurrent instability in revision total hip arthroplasty (rTHA) requires a personalized approach, as traditional constrained liners often yield suboptimal results due to locking-mechanism failure and limited impingement-free range of motion. This study aimed to evaluate the mid-term clinical outcomes of a novel constrained acetabular liner (CAL) when utilized as a patient-specific solution for a high-risk cohort undergoing complex rTHA. By tailoring the constraint to individual biomechanical deficits, this next-generation device seeks to mitigate historic failure modes. METHODS:We retrospectively reviewed 32 patients who underwent 37 rTHA procedures with a next-generation CAL at a single urban academic center between March 2017 and October 2023. Average follow-up was 4.7 years (range, 0.3 to 9.7 years). The most common indication for rTHA was instability (70.3%), followed by infection (16.2%), aseptic loosening (10.8%), and polyethylene wear (2.7%). Just over one third of patients (37.5%) had undergone a prior revision. Preoperative constructs included fixed-bearing (37.8%), dual-mobility (32.4%), CAL (24.3%), static spacer (2.7%), and hemiarthroplasty (2.7%). RESULTS:In most procedures (70.3%), the CAL was implanted into a pre-existing acetabular cup, whereas 29.7% involved both cup and liner revision. Following rTHA, no cases of implant wear, breakage, acetabular cup aseptic loosening, or periprosthetic fracture were observed. Six patients (18.8%) underwent a total of sixteen subsequent reoperations after CAL implantation-10 for instability and 6 for infection. Among instability-related reoperations, 4 involved revision to a new next-generation CAL. Survivorship free from all-cause reoperation was 83.8% at one year and 72.6% at latest follow-up. CONCLUSIONS:This study demonstrates favorable mid-term clinical outcomes and reoperation-free survivorship following complex revision THA using a novel constrained acetabular liner system. For patient cohorts suffering from severe recurrent dislocation, this next-generation CAL provides an effective, tailored tool in the surgical armamentarium by adapting to unique patient anatomy and soft-tissue compromises. Further research with larger sample sizes and extended follow-up is needed to assess long-term durability.

BACKGROUND AND AIM/OBJECTIVE:Recent studies examining synovial fluid analysis to differentiate causes for aseptic revision total knee arthroplasty (rTKA) were limited to aseptic loosening and instability. This study aims to establish specific serological and synovial profiles for various rTKA etiologies. METHODS:We retrospectively reviewed patients who underwent aseptic rTKA at a single academic institution between 2012 and 2023. Inclusion required complete serum inflammatory markers (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) and synovial fluid differentials within three months pre-operatively. Periprosthetic joint infections were strictly excluded utilizing the 2018 International Consensus Meeting criteria. In total, 156 patients were included and stratified into five aseptic etiologies: aseptic loosening (50.6%), instability (28.2%), arthrofibrosis (16.7%), liner wear (2.6%), and component malposition (1.9%). Serological markers were evaluated utilizing a multivariate general linear model adjusting for patient demographics, while synovial markers were assessed via Welch's Analysis of Variance (ANOVA) and Games-Howell post-hoc testing. RESULTS:Multivariate analysis demonstrated that the underlying rTKA indication was not a significant independent predictor of elevated ESR (P = 0.661) or CRP (P = 0.947). Welch's ANOVA revealed significant differences in the percentage of synovial monocytes (P < 0.001) and lymphocytes (P = 0.010), alongside the polymorphonuclear cells/monocyte (P = 0.030) and lymphocyte/monocyte (P = 0.005) ratios. Games-Howell post-hoc testing demonstrated the tibial liner wear group exhibited significantly higher monocyte percentages, paired with lower lymphocyte percentages and cellular ratios, compared to other aseptic etiologies. CONCLUSIONS:This study revealed that routine systemic inflammatory markers and standard synovial fluid cell counts do not significantly vary among the common etiologies of aseptic rTKA. Nonetheless, tibial polyethylene liner wear appears to elicit an exploratory, monocyte-predominant and lymphocyte-depleted local macrophage response that is absent in other mechanisms of aseptic failure. Further research with larger cohorts is warranted to validate this association and explore its potential as a diagnostic tool.

INTRODUCTION/BACKGROUND:Intraprosthetic dislocation (IPD) is a rare but potentially catastrophic complication of dual-mobility (DM) implants, defined by dissociation of the inner femoral head from the polyethylene liner. Modular dual-mobility (MDM) designs were introduced to improve intraoperative flexibility and expand indications for DM technology. However, increasing reports of IPD have raised concerns that implant design and manufacturing differences may influence risk. The true incidence of IPD across MDM manufacturers remains unclear. METHODS:A systematic search of PubMed, Embase, and Web of Science was performed. Studies reporting IPD incidence and stratified outcomes by implant manufacturer were included. A random-effects proportion meta-analysis was conducted to estimate pooled IPD incidence and revision rates overall and by manufacturer. RESULTS:Of 523 identified articles, 32 met inclusion criteria, representing 3996 implants (2711 primary; 1285 revision). Mean follow-up was 3.48 years and mean age was 67.48 years. The overall IPD incidence was 0.38% (15/3996), with a pooled estimate of 0.1% (95% CI, 0-0.5%). Stratified analyses showed IPD rates of 0% for Stryker (95% CI, 0-0.7%), 0% for Zimmer (95% CI, 0-100%), and 0% for Groupe Lépine (95% CI, 0-100%). Reoperation rates were 1.4% (95% CI, 0.9-2.1%) in primary and 8.3% (95% CI, 6.0-11.3%) in revision THA. CONCLUSIONS:The incidence of IPD in MDM implants is low, with pooled rates remaining below 1%. Revision rates were modest and consistent with published data on complex hip arthroplasty. No significant differences between manufacturers were detected, though findings are limited by the small number of non-Stryker implants reported. These findings suggest that MDM designs appear safe with overall low numbers of IPD-related complications, however, larger registry-based studies are needed to better define potential design-related differences in IPD risk.

Obesity, metabolic syndrome, and type 2 diabetes mellitus contribute to osteoarthritis (OA) through adipokine signaling, systemic inflammation, oxidative stress, and insulin resistance, affecting both weight-bearing and non-weight-bearing joints. Glucagon-like peptide-1 receptor agonists have rapidly expanded in use and promises musculoskeletal benefits beyond weight loss. Preclinical studies demonstrate anti-inflammatory, analgesic, and chondroprotective effects, including reduced cytokine activity and cartilage matrix degradation. Randomized trials in knee OA show significant weight loss with modest improvements in pain and function, while observational data suggest possible cartilage preservation and reduced surgical rates, though results are mixed. Evidence in inflammatory arthritis is promising but limited.

INTRODUCTION/BACKGROUND:Patellar resurfacing in primary total knee arthroplasty (TKA) has been debated for decades. This study aimed to evaluate cost-effectiveness and clinical outcomes of patellar resurfacing in modern TKA at a high-volume arthroplasty center. METHODS:A retrospective study was conducted on 4,534 patients who underwent unilateral, elective, primary TKA from 2021 to 2024 at an urban academic institute. Patients were stratified by patellar resurfacing: resurfaced (n=3,753) or not (n=781). Baseline characteristics, operative costs [implants, anesthesia, operating room time], and postoperative outcomes (revision incidence) were collected. The median follow up was 2.0 years (1.0- 4.8). The individual cost of patellar component was adjusted for implant manufacturer and cementation out of total implant cost. Multivariable regression analysis determined added operating room time (ORT) due to patellar resurfacing, controlling for body-mass index, usage of robotics, navigation and cementation. Relative costs of added ORT and the patellar component were compared to total implant and procedure costs of patellar-resurfacing operations. RESULTS:The patellar component accounted for an average of 7.9% of the total implant cost in patellar-resurfacing operations. Patellar-resurfacing operations had longer operative times (112.2 vs. 105.4 minutes, P<0.001), and multivariable regression determined patellar resurfacing is associated with an added 6.3 minutes of total ORT (P<0.001). The patellar component implant cost and the cost of added ORT due to resurfacing accounted for 4.5% of the total procedure cost in resurfaced group. Resurfaced group had an overall 5% higher total operative cost than the non-resurfaced group. No differences existed in length of stay (LOS), discharge disposition, or all-cause and patella-specific revision incidence. CONCLUSION/CONCLUSIONS:We found that patellar resurfacing was associated with longer operative times and greater implant and procedure costs, although there was no effect on LOS, discharge disposition, or all-cause and patella-specific revision incidence. Ultimately, the decision to resurface the patella in primary TKA should be based on patient-specific indications and clinical judgment. However, it is important to consider the additional cost associated with this procedure.

BACKGROUND/UNASSIGNED:Dual-mobility (DM) articulations and porous acetabular shells are increasingly used to address instability and mechanical loosening in revision total hip arthroplasty (rTHA). However, reports of longer-term outcomes with the new generation of DM articulations and porous shells remain limited. Our study reports the use and outcomes of a cemented monoblock DM cup in a fully porous acetabular shell in complex rTHA cases with midterm follow-up. METHODS/UNASSIGNED:A retrospective study was conducted of rTHAs with an acetabular construct of a monoblock DM cup cemented into a fully porous acetabular shell between June 2016 and December 2019. Baseline demographics, operative information, and outcomes were gathered for a total of 55 patients. Ten patients died, and 4 were lost to follow-up at 5 years; 41 patients were included in the analysis of midterm outcomes. RESULTS/UNASSIGNED:The most common indications for rTHA were acetabular component loosening (43.6%), periprosthetic joint infection (PJI) (16.4%), dislocation (12.7%), and periprosthetic fracture (9.1%). Preoperative acetabular bone loss assessment found 43.7% type IIA, 9.1% IIB, 20.0% IIC, 23.6% IIIA, and 3.6% IIIB according to the Paprosky classification. Six patients (10.9%) were readmitted within 90 days for PJI (n = 5; 9.1%) or dislocation (n = 1; 1.8%). Four patients (9.8%) required revision of the construct: 2 for PJI, 1 case of instability, and 1 case of aseptic loosening of the acetabular component with significant acetabular bone loss. The average time to revision was 1.4 years (range, 0.1-3.8 years). The mean follow-up period was 6.4 years (range, 4.7-8.2 years). The cup in cup construct had an all-cause survivorship of 95.8% and 90.0% at 1 and 5 years, respectively, and aseptic survivorship rates of 97.9% and 94.7% at 1 and 5 years, respectively. CONCLUSIONS/UNASSIGNED:This cohort of 55 patients who underwent complex rTHA with a monoblock DM cup cemented into a porous acetabular shell exhibited reliable fixation and low revision rates. In complex revision cases where instability and inadequate fixation are concerns, these outcomes support continued consideration and use of this unique and durable construct.

BACKGROUND:This study evaluated functional limb-length (LL) and coronal-alignment preservation after revision total knee arthroplasty (rTKA) relative to contralateral and pre-rTKA baselines, examining their association with patient-reported outcome measures (PROMs). METHODS:We retrospectively reviewed 70 rTKA patients with pre- and post-rTKA full-length radiographs. Functional LL preservation was defined as ± 10 mm of the target. Patient-reported outcomes-including Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) and Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Intensity and Pain Interference-were compared across LL (shortened/preserved/over-lengthened) relative to contralateral/pre-rTKA baselines and coronal alignment (preserved/changed) categories. Indications included aseptic loosening (31.4%), instability (30.0%), arthrofibrosis (14.3%), periprosthetic joint infection (12.9%), and insert wear (11.4%). RESULTS:The post-rTKA LL was preserved relative to the contralateral LL in 68.6% of the patients and pre-rTKA LL in 47.1%. Coronal alignment was preserved in 64.3%. PROM improvements were comparable across categories (P > 0.05). When referencing the contralateral limb, only the over-lengthened cohort achieved the minimal clinically important difference (MCID) across all PROMs at three months; at one year, all cohorts achieved MCID for KOOS, JR, and pain intensity, but missed the pain interference threshold. When referencing the pre-rTKA state, preserved and over-lengthened cohorts achieved MCID across all PROMs at three months; at one year, all cohorts sustained the MCID across all three outcome domains. The preserved alignment cohort achieved MCID across all PROMs, while the changed alignment cohort missed the threshold for pain interference. CONCLUSIONS:Revision TKA preserved functional LL and coronal alignment in approximately two-thirds of cases. Although PROMs were comparable among categories, early MCID achievement was associated with over-lengthening relative to the contralateral limb and avoiding shortening relative to the pre-rTKA state. At one year, preserving pre-rTKA coronal alignment provided superior pain interference relief, sustained only when evaluated relative to the pre-rTKA baseline.

INTRODUCTION/BACKGROUND:Same-day discharge (SDD) following primary total hip arthroplasty (THA) is increasingly utilized and has been shown to be safe in appropriately selected patients. However, limited data compare whether specific patient risk factors for postoperative readmission exert different magnitudes of influence in the SDD versus in the non-same-day discharge (NSDD) cohorts. Identifying risk factors that disproportionately affect SDD patients may refine SDD selection criteria and improve postoperative safety.: METHODS: This retrospective cohort study evaluated 11,245 patients who underwent primary elective THA at a single institution between 2017 and 2024. Patients were grouped by discharge timing into SDD (n = 2,318) and NSDD (n = 8,927). The primary outcome was orthopaedic-related hospital readmission within 90 days. Multivariable logistic regression models were constructed separately for SDD and NSDD cohorts to identify independent predictors of readmission. Adjusted odds ratios were compared between cohorts using z-tests to assess differences in effect magnitude. A sub-analysis was performed among cases by high-volume surgeons (≥ 100 THAs/year). RESULTS:The SDD patients had a significantly lower 90-day readmission rate compared with NSDD patients (0.8 versus 2.1%, P < 0.001). In SDD patients, smoking (odds ratio (OR) 13.98, P < 0.01) and older age (OR 1.13, P < 0.01) were strongly associated with readmission, while women were protected. In NSDD patients, higher body mass index and American Society of Anesthesiologists score ≥ III increased readmission risk, whereas partner status, higher hemoglobin, and non-White race were protective. Effect-size comparisons demonstrated that smoking (z = 4.34, P < 0.001) and age (z = 3.65, P < 0.001) had stronger associations with readmission in SDD patients than in NSDD patients. Readmission etiologies were similar between groups. Findings were consistent in the high-volume surgeon sub-analysis. CONCLUSIONS:While SDD after primary THA is associated with low overall readmission rates, smoking and advanced age confer disproportionately greater readmission risk when same-day discharge is pursued. These findings suggest that smoking status and age may warrant additional attention during preoperative counseling and individualized same-day discharge decision-making, while recognizing that absolute readmission rates remain low.

BACKGROUND/UNASSIGNED:Solid organ transplant (SOT) recipients undergoing total joint arthroplasty (TJA) may face elevated perioperative risk because of chronic immunosuppression, medical comorbidity, and organ-specific physiologic considerations. Although intravenous tranexamic acid (TXA) is widely used during TJA to reduce perioperative blood loss, evidence regarding outcomes among SOT recipients receiving TXA remains limited. METHODS/UNASSIGNED:A retrospective review was performed of 29,240 consecutive primary TJA patients who all received intraoperative intravenous TXA between June 2011 and March 2025. Patients undergoing unicompartmental knee arthroplasty, hemiarthroplasty, TJA for fracture, bilateral procedures, revision procedures, or those with less than 90 days of postoperative follow-up were excluded. SOT history was identified using diagnosis and procedural codes and verified by manual review. Outcomes included 90-day deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI), operative time, and hospital length of stay (LOS). RESULTS/UNASSIGNED:Sixty-six patients with verified SOT were identified. The most common transplant types were kidney (59%), liver (24%), and heart (9%). One SOT patient experienced a 90-day VTE event compared with 95 control patients (1.5% versus 0.3%, P = 0.20). There were no PEs or MIs in the SOT cohort, compared with PE and MI rates of 0.2% and 0.01% in controls, respectively (P > 0.05 for both). Operative times were similar between groups (100.8 versus 108.5 min, P = 0.11), while LOS was significantly longer among SOT recipients (86.2 versus 43.8 h, P < 0.001). CONCLUSION/UNASSIGNED:In this retrospective cohort of primary TJA patients who all received intraoperative intravenous TXA, SOT recipients had low observed rates of VTE, PE, and MI. Because all patients received TXA and the SOT cohort was small, these findings should be interpreted as comparative observational safety data rather than evidence that TXA independently increases or does not increase thromboembolic risk in this population.