Faculty Bibliography

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.

BACKGROUND:Studies on patients have shown that normal anatomic motion is often not achieved with current total knee arthroplasty (TKA) designs. The purpose of this study was to determine whether anatomic motion could be restored using a design where intercondylar guiding surfaces were positioned between the medial and lateral femoral condyles. METHODS:A crouching machine was constructed, which included simulations of the collateral ligaments, the quadriceps mechanism, the hamstrings, and the gastrocnemius. Medial pivot, medially congruent, ultracongruent, and replica intercondylar TKAs were designed and 3-dimensionally printed. The femoral-tibial kinematics were measured by determining lateral and medial contacts, as the knee underwent flexion and extension from 12 to 130°. RESULTS:The replica intercondylar design showed an almost constant position of the medial contact, with a progressive posterior displacement laterally during flexion. In contrast, the other designs showed nearly parallel motion with minimal variation in contact location. CONCLUSIONS:It was concluded that intercondylar guiding surfaces could produce anatomical motion in a TKA where the cruciate ligaments were resected.

While there have been great advancements in total knee arthroplasty (TKA) over the past 50 years, anterior knee pain (AKP) remains the most common concern among patients postoperatively. Despite exhausting evidence supporting no clinical difference in AKP with resurfaced vs. unresurfaced patellae in TKA, 87% of TKAs are resurfaced in the United States, compared with 2% in other countries. These large practice variations underscore a lack of consensus regarding the role of the patella and the approach to the anterior compartment of the knee in TKA. The aim of this review was to go beyond patellar resurfacing and describe the effects that surgical technique and implant design may have on AKP in current TKA.

BACKGROUND:Unicompartmental knee arthroplasty (UKA) may offer advantages over total knee arthroplasty (TKA) for select patients, but implant failure leading to conversion to TKA remains a concern. The purpose of this study was to compare two-year conversion rates to TKA following UKA performed by arthroplasty fellowship-trained surgeons versus surgeons who did not have arthroplasty fellowship training at a single academic institution. METHODS:A retrospective review was performed of primary UKAs conducted at a single academic institution between 2010 and 2023, which had at least two years of follow-up and implant data available. Cases were grouped based on surgeon fellowship training. Demographics, operative characteristics, postoperative complications, and conversion to TKA were analyzed at two and five years, with characterization of all TKAs performed within five years. Implant survivorship was assessed using Kaplan-Meier analysis; group comparisons used Chi-square or Fisher exact tests as appropriate. A total of 413 UKAs were included, with 202 performed by arthroplasty-trained surgeons and 211 by non-arthroplasty-trained surgeons. Patients in the arthroplasty-trained group were older (mean 62.9 versus 58.5 years, P<0.001) and had higher Charlson Comorbidity Index scores (mean 5.03 versus 4.6, P<0.001). Technology utilization differed, with greater robotic use among non-arthroplasty-trained surgeons (84.4 versus 59.4%, P<0.001). RESULTS:At two years, conversion to TKA occurred in 2.5% of cases performed by arthroplasty-trained surgeons compared with 5.7% in the non-arthroplasty-trained group (P=0.049). Overall complication rates did not differ. Lateral UKA demonstrated significantly worse survivorship than medial UKA (log-rank P=0.0004). Among 29 TKAs performed within five years, indications and operative characteristics were similar between groups, but revision surgeon specialty differed significantly (P=0.001). CONCLUSIONS:Arthroplasty fellowship training was associated with a lower observed two-year conversion rate to TKA despite treatment of older, more comorbid patients and lower utilization of robotics. Failure patterns and survivorship beyond two years were similar.

BACKGROUND:Total hip arthroplasty (THA) is commonly performed using either an anterior- or posterior-based approach (AA or PA), with similar long-term outcomes. However, operative timings, including time for patient positioning, device implantation, wound closure, and total operating room (OR) time, may differ between these approaches. This study assessed differences in various OR timings between AA and PA for primary THA. METHODS:A retrospective review was performed of all patients who underwent primary, unilateral, elective THA at our large urban academic medical center between January 1, 2019, and January 31, 2025. Patient demographics and operative parameters were determined from clinical and operative records. Surgeons who began practicing during the study period had their first 50 cases excluded. Perioperative timings were compared between approaches. Multivariable regression analyses controlled for age, American Society of Anesthesiologists status, body mass index, cementation, robotic use, navigation assistance use, discharge disposition, sex, smoking status, and year of surgery. There were 8,120 procedures included (4,670 PA and 3,450 AA). RESULTS:The AA had shorter total OR time (156.7 versus 167.4 minutes, P < 0.001). Regression analysis found AA was associated with longer implantation time (+3.3 minutes, P < 0.001), but shorter set-up time (-2.0 minutes, P < 0.001), closure time (-7.5 minutes, P < 0.001), overall operative time (-4.2 minutes, P < 0.001), and take-down time (-3.6 minutes, P < 0.001). Cement fixation had an increased effect on AA operative times compared to PA (+28.9 versus +14.4 minutes; P < 0.001). CONCLUSIONS:Anterior approach THA procedures displayed faster set-up, closure, take-down, and OR times compared to PA. Controlling for covariates, AA reduces total OR time by nearly 10 minutes, although operative time with AA is more significantly impacted by cementation. Further studies investigating the cost analysis of AA versus PA are needed to contextualize these findings regarding timing.

PURPOSE/UNASSIGNED:The impact of altering a patient's hip offset during total hip arthroplasty (THA) on periprosthetic fracture risk is unknown. The purpose of this study was to compare periprosthetic fracture risk in patients where THA offset was "matched" to their contralateral native hip versus those where offset was mismatched. MATERIALS AND METHODS/UNASSIGNED:-tests and chi square analyses were used for data comparison. Relative risk (RR) with a 95% confidence interval (CI) was then calculated. RESULTS/UNASSIGNED:=0.015). CONCLUSION/UNASSIGNED:Failure to restore a patient's offset during THA is associated with increased rates of periprosthetic fracture. Although restoration of native hip anatomy is an important technical consideration of this procedure, alterations in the hip lever arm may predispose patients to periprosthetic fracture.

BACKGROUND:Solid organ transplant (SOT) patients undergoing total joint arthroplasty (TJA) may be at higher risk for complications due to complex medical and surgical histories, chronic immunosuppressive medications, and significant ongoing comorbidities. This study aimed to evaluate postoperative outcomes following primary, elective TJA in patients with a history of SOT. METHODS:We retrospectively reviewed 53,043 primary, elective TJA patients from 2011 to 2025. Patients were screened for SOT history prior to TJA. All SOT patients were taking some form of immunosuppressive medication following their transplantation. Demographics, SOT details, and surgical data were obtained. SOT patients (n = 70) underwent a nearest-neighbor 1:3 propensity-score matching to non-SOT (NSOT) controls (n = 210) based on age, sex, smoking, Charlson Comorbidity Index, body-mass index, and TJA indication. Kidney transplants were most common (61.4%), followed by liver (24.3%), and heart (8.6%). Differences in surgical outcomes and postoperative complications between the patients were investigated using Chi-squared tests, independent t-tests and effect size (ES) estimates. Baseline characteristics did not differ between the groups (P > 0.05). RESULTS:SOT patients had significantly longer hospital stays (92 vs. 51 h, P < 0.001, ES = 0.82), higher rates of discharge to skilled nursing facilities (SNF) (15.7% vs. 5.7%, P = 0.014, ES = 0.17) and all-cause 90 day readmissions (15.7% vs. 6.7%, P = 0.040, ES = 0.12), primarily driven by non-surgical reasons (14.3% vs. 4.3%, P = 0.010, ES = 0.16) compared to NSOT patients. All-cause revision rates were comparable between SOT and NSOT patients (4.3% vs. 3.8%, P = 0.999), including aseptic (2.9% vs. 1.9%, P = 0.642) and septic causes (1.4% vs. 1.9%, P = 0.999). CONCLUSIONS:Despite higher rates of SNF discharge and non-surgical 90 day readmissions, SOT patients achieved similar all-cause, septic, and aseptic revision rates, compared to NSOT patients. These findings suggest that compared to well-matched comorbid controls, SOT patients can safely undergo elective TJA with comparable revision risk. Enhanced perioperative care may help reduce readmission risks in this complex population.

BACKGROUND/UNASSIGNED:Arthrofibrosis represents a source of patient dissatisfaction following total knee arthroplasty (TKA). The purpose of this systematic review and meta-analysis was to evaluate the efficacy of perioperative angiotensin II receptor blockers (ARBs) as anti-fibrotic agents in patients undergoing total knee arthroplasty (TKA). METHODS/UNASSIGNED:The Medline, Embase and Cochrane library databases were systematically reviewed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The outcome measures of interest were postoperative knee range of motion (ROM), rates of manipulation under anesthesia (MUA) and revision rates. RESULTS/UNASSIGNED: = 0.3349). CONCLUSION/UNASSIGNED:This systematic review and meta-analysis found that the utilization of perioperative ARBs were not associated with superior postoperative knee ROM nor lower rates of MUA in patients undergoing TKA. Additionally, no difference in revision TKA rates existed between patients in the ARB cohort compared to the control cohort. Based on the current available data, it is the author's current recommendation that perioperative ARB usage is not indicated in the setting of TKA for the prevention of arthrofibrosis. However, this analysis should be interpreted in light of the low level of evidence and under-reporting of data of the included studies. Thus, higher-level evidence, prospective, comparative studies should be conducted to definitively identify if perioperative ARBs can be utilized as effective anti-fibrotic agents in the setting of TKA.

INTRODUCTION/BACKGROUND:Use of the direct anterior approach (DAA) in total hip arthroplasty (THA) has increased, with suggested benefits of faster recovery and less pain. However, consensus regarding the optimal approach is lacking. This study compared post-operative pain, functional recovery, and opioid use between DAA and posterior approach (PA) THA. METHODS:-tests. RESULTS: 0.001), but these small differences do not reflect clinical significance. MME comparison showed a trend towards decreased opioid consumption within the DAA cohort, but the clinical relevance of these differences is unknown. CONCLUSIONS:Pain, function, and opioid use were largely comparable between DAA and PA, with minor statistical differences unlikely to be clinically meaningful.

BACKGROUND:Robotic and navigation-assisted total knee arthroplasty (TKA) systems aim to optimize surgical performance; however, their influence on the speed of functional recovery remains unclear. This study compared the time to achieve a minimal clinically important difference (MCID) among patients undergoing robotic-assisted (RA), navigation-assisted (NA), and conventional TKA using Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) questionnaires. METHODS:This retrospective cohort study included patients undergoing primary TKA for osteoarthritis at a tertiary academic center from July 2017 to July 2024. Inclusion required preoperative and postoperative KOOS-JR scores within 12 months of surgery. Exclusion criteria were non-osteoarthritis indications, bilateral procedures, or revision within one year. The MCID was defined using both anchor-based and distribution-based methods. The time to MCID was analyzed using multivariable interval-censored accelerated failure time models, accounting for clinical and demographic variables and the operating surgeon. A total of 2,002 patients met the inclusion criteria: 433 (21.6%) underwent RA-TKA, 713 (35.6%) NA-TKA, and 856 (42.8%) conventional TKA. RESULTS:Both technology-assisted approaches were associated with faster MCID achievement compared to conventional TKA. Using distribution-based thresholds, NA-TKA achieved MCID 29% faster (time ratio [TR] = 0.71, 95% confidence interval (CI): 0.58 to 0.88, P = 0.002) and RA-TKA 26% faster (TR = 0.74, 95% CI: 0.57 to 0.95, P = 0.018), with covariate-standardized estimated median times of 19.9, 20.7, and 28.0 days, respectively. Using anchor-based thresholds, NA-TKA achieved MCID 27% faster (TR = 0.73, 95% CI: 0.57 to 0.95, P = 0.017) and RA-TKA 26% faster (TR = 0.74, 95% CI: 0.55 to 1.00, P = 0.050), with corresponding median times of 52.8, 53.5, and 71.9 days. The one-year MCID attainment rates were similar across all techniques (P > 0.6 for both definitions). CONCLUSIONS:Both RA-TKA and NA-TKA were associated with 26 to 29% faster achievement of clinically meaningful improvement compared with conventional TKA, corresponding to approximately seven to 19 fewer days to reach MCID, despite similar one-year attainment rates. Prospective multicenter studies are needed to validate these results and determine whether accelerated recovery translates to advantages in quality of life, healthcare utilization, and patient satisfaction.