Faculty Bibliography

BACKGROUND:With the increased rates of revision total hip (rTHA) and total knee arthroplasty (rTKA), the financial burden of these procedures is at risk of straining the healthcare system. Our study sought to create a model to evaluate the cost-effectiveness of rTKA and rTHA performed by high-volume (HV) and low-volume (LV) surgeons. METHODS:percentile in annual volume were classified as HV surgeons and the remainder were classified as LV surgeons. Previously published cost estimates were utilised for operative time, hospital length of stay (LOS), discharge disposition, 90-day readmission, and 1-year re-revision. RESULTS: < 0.001). Both groups had equivalent discharge disposition, 90-day readmission, and 1-year re-revision. HV surgeons had lower estimated mean costs for rTHA ($22,027.81 vs. $24,617.39) and rTKA ($20,343.23 vs. $18,554.67). CONCLUSIONS:HV surgeons have a lower estimated mean cost for both rTHA and rTKA. Healthcare systems may benefit from having rTHA and rTKA procedures performed by HV surgeons who are able to perform these revision procedures for a lower cost without negatively impacting patient 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:Cementless total knee arthroplasty (TKA) has recently regained popularity, yet data has raised concerns about rates of arthrofibrosis following these procedures. The purpose of this study was to utilize the American Joint Replacement Registry to compare rates of early manipulation under anesthesia (MUA) in cementless and cemented primary TKAs that use technology or manual instrumentation. METHODS:We queried the American Joint Replacement Registry for all patients ages 18 to 95 years who underwent cemented or cementless primary TKA over a 7-year period. Patients were stratified based on whether technology (robotics or computer-assisted navigation) was used during the primary surgery. Groups were then compared for rates of MUA within 90-day of the index surgery using multivariable logistic regression models. A total of 340,841 cases were included in the study, 78,397 (23%) of which used technology and 262,444 (77%) which did not. Within the technology cohort, there were 51,500 (65%) robotic and 26,897 (35%) navigated cases. There were 65% of technology-assisted TKAs and 92% of manual TKAs cemented. RESULTS:In the technology group, multivariable analysis demonstrated significantly higher odds of MUA in cemented TKAs compared to cementless (odds ratio [OR] 1.95, 95% confidence interval [CI] [1.06 to 3.59]; P = 0.031). Robotic cases had significantly higher odds of MUA with cemented compared to cementless implants (OR 2.38, 95% CI [1.27 to 4.46]; P = 0.007), while there was no difference in MUA related to cementation in the navigated cases (OR 3.53, 95% CI [0.48 to 25.95]; P = 0.22). In the manual group, there were no significant differences in MUA rates related to cementation use (OR 1.14, 95% CI [0.8 to 1.64]; P = 0.46). CONCLUSIONS:Cementless TKA did not increase odds of MUA. In further analyzing cement use into technology and manual cohorts, robotic-assisted cemented TKAs had higher rates of early MUA than cementless. Identification of risk factors leading to early arthrofibrosis may be patient dependent and further study is required to elucidate any surgical considerations.

BACKGROUND:Recovery after total knee arthroplasty (TKA) shows considerable variability in both pain relief and functional improvement. The Knee Injury and Osteoarthritis Outcome Score (KOOS-JR) is a widely used measure for evaluating these outcomes. This study aimed to identify distinct latent recovery trajectories, which represent underlying, unobserved patterns of postoperative recovery inferred from KOOS-JR scores, and to explore patient characteristics associated with these trajectories. METHODS:This retrospective cohort study analyzed patients who underwent primary TKA for osteoarthritis at a tertiary academic center from January 2020 to March 2023. Inclusion criteria required patients to have completed a preoperative KOOS-JR questionnaire and at least two postoperative follow-ups at 1, 3, 6, or 12 months. Exclusion criteria included bilateral or revision procedures. Collected characteristics included age, sex, Body Mass Index, American Society of Anesthesiologists physical status classification, race, smoking status, procedure type, anesthesia type, length of hospital stay, and discharge disposition. Growth mixture modeling was used to model recovery trajectories, with associations evaluated using the "three-step approach." Model fit was assessed using the Akaike and Bayesian Information Criteria, Vuong-Lo-Mendell-Rubin likelihood ratio, posterior probabilities, and entropy values. RESULTS:Of 700 eligible patients, growth mixture modeling identified two recovery trajectories: 95.4% of patients (trajectory 1 [T1]) demonstrated steady improvement, while 4.6% (trajectory 2 [T2]) began with lower KOOS-JR scores (mean 9.7 vs. 47.9 for T1) but recovered to near T1 levels by 1 month. Trajectory 2 patients were markedly younger (mean 64 vs. 67 years), had higher Body Mass Index (36 vs. 31), included more Black or African American individuals (38% vs. 20%), and were more frequently discharged to rehabilitation facilities (16% vs. 3.3%; all P < 0.05). Each additional year of age reduced the likelihood of following T2 by 4% (odds ratio = 0.96, 95% confidence interval, 0.92 to 0.99; P = 0.016), while discharge to rehabilitation increased the likelihood 6-fold (odds ratio = 6.22, 95% confidence interval, 1.89 to 17.8; P = 0.001). CONCLUSION/CONCLUSIONS:This study identified two distinct recovery trajectories after TKA, with notably no trajectory emerging showing decline or stagnation from preoperative levels. Despite lower baseline scores, patients in T2 achieved substantial recovery, suggesting TKA provides meaningful improvement even for those with substantially compromised function. The findings also highlight the need to explore whether rehabilitation discharge directly influences the observed postoperative gains.

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:Obtaining an accurate preoperative diagnosis of periprosthetic joint infections (PJI) is challenging, making differentiating between septic and aseptic failures difficult. We sought to identify the value of common serum biomarkers and evaluate the accuracy of three ratios in the diagnosis of PJI after primary total knee arthroplasty (TKA): albumin-globulin ratio (AGR), C-reactive protein-albumin ratio (CAR), and C-reactive protein-AGR ratio (CAGR). METHODS:Patients undergoing PJI and aseptic revisions after TKA between 2011 and 2021 were retrospectively reviewed at a single institution. Only patients who had reported serum white blood cell (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), albumin (Alb), and total protein (TP) were included. Areas under the curve (AUCs), which optimize diagnostic performance by balancing sensitivity and specificity at a specific cutoff, were calculated for each individual biomarker and the three ratio groups: AGR = Alb / [TP - Alb], CAR = CRP / Alb, and CAGR = CRP / AGR). Higher AUCs indicate improved identification of PJI while reducing misclassification. RESULTS:Out of the 126 included cases, 89 were confirmed PJIs and 37 were aseptic revisions. Among the single and combination serum biomarkers, the AUCs were as follows: CRP (0.85), ESR (0.76), Alb (0.81), AGR (0.78), CAR (0.87), and CAGR (0.87). The CAR demonstrated excellent accuracy at a cutoff of 2.46, with a sensitivity of 0.74 and specificity of 0.84. CAGR also demonstrated excellent accuracy at a cutoff of 7.09, with a sensitivity of 0.80 and specificity of 0.78. CONCLUSION/CONCLUSIONS:The CRP, CAR, and CAGR showed an excellent diagnostic accuracy as markers for PJI. In patients undergoing revision TKA, common serum biomarkers such as Alb, TP, CRP, and ESR can be obtained, and CAR or CAGR ratios can be calculated to aid in the diagnosis of PJI, especially in cases where synovial analysis is inconclusive, allowing for better clinical decision-making.

Total hip arthroplasty (THA) is one of the most common and successful procedures for the treatment of end-stage hip arthritis. However, in certain complex scenarios, THA can present important and unique challenges, specifically following acetabular fractures in adolescent patients, following failed fixation of proximal femoral fractures, and in developmental dysplasia of the hip (DDH). As these cases involve distorted anatomy, poor bone quality, retained hardware, and previous surgeries, detailed planning, specialized instrumentation and implants, and novel surgical techniques are required. This narrative review examines the challenges, surgical considerations, outcomes, and complications in complex THA management.

INTRODUCTION/BACKGROUND:Total knee arthroplasty can substantially affect global lower limb alignment. However, its specific impacts on ankle and subtalar joint alignment remain poorly understood. This study investigates changes in ankle and subtalar alignment following varying degrees of varus/valgus knee correction in order to further our understanding of this association. MATERIALS AND METHODS/METHODS:This retrospective study included 100 patients who underwent surgery for primary osteoarthritis. Patients diagnosed with conditions other than primary knee OA and those with incomplete or poor-quality imaging were excluded. Patients were categorized into four groups by the degree of intraoperative coronal knee alignment correction: Group 1 (< 10° varus, n = 37), Group 2 (≥ 10° varus, n = 30), Group 3 (< 10° valgus, n = 18), and Group 4 (≥ 10° valgus, n = 15). Hip-knee-ankle angle, tibial plafond inclination, talar inclination, tibiotalar tilt, and subtalar varus-valgus angle, were measured preoperatively and postoperatively on full-length, standing, anteroposterior X-ray images. RESULTS:TKA resulted in postoperative changes in all measured angles regardless of the degree of varus/valgus correction. Notably, ≥ 10° valgus correction led to statistically significant postoperative alterations in ankle and subtalar alignment: tibial plafond inclination from 84.9 to 89.5° (Δ 4.6, range,1.5-7.8, P <.01), tibiotalar tilt from 83.1 to 89.3° (Δ 6.2, range,1.1-9.6, P =.02), and subtalar varus-valgus angle from 66.4 to 72.6° (Δ 6.2, range,1.9-12.1, P <.01). CONCLUSION/CONCLUSIONS:While knee deformity correction during TKA generally realigns the ankle and subtalar joint, our study has shown that large valgus knee correction (≥ 10°) during TKA significantly alters ankle and subtalar joint alignment. Thus, potentially leading to unfavorable postoperative outcomes in patients with abnormal or stiff joints. We recommend that future studies investigate the long-term effects of large valgus knee corrections during TKA on ankle and subtalar joint alignment and their impact on postoperative outcomes.

The efficacy of "Expanded Gram-Negative Antimicrobial Prophylaxis" (EGNAP) in preventing postoperative infections has been previously reported in total hip arthroplasty (THA). However, it remains unclear as to whether these benefits extend to total knee arthroplasty (TKA). This study investigated whether adding EGNAP to our institution's preoperative antibiotic prophylaxis protocol would affect periprosthetic joint infection (PJI) risk in TKA patients. We retrospectively reviewed 10,666 elective, unilateral, primary TKA cases performed at a single-specialty tertiary academic hospital from 2018 to 2022. Before June 2021, all patients received 2 g of cefazolin for 24 h as part of the prophylactic antibiotic protocol. After June 2021, gentamicin or aztreonam (EGNAP) was added to the protocol for all TKA patients. Patients were grouped based on whether they received EGNAP or not (control group) before surgery. The groups were propensity score-matched in a 2:1 ratio. PJI and nephrotoxicity (using RIFLE criteria) risk was compared. After matching, the final study population consisted of 3007 patients in the non-EGNAP group and 1503 patients in the EGNAP group. There was no significant difference between the EGNAP and no EGNAP groups in the overall incidence of PJI (1.9% vs. 2.0%; p = 0.111) or the incidence of Gram-positive PJIs (0.3% vs. 0.8%; p = 0.103). The incidence of Gram-negative PJIs was 0.5% in the EGNAP group and 0.4% in the no EGNAP group, which was also not different between the groups (p = 0.692). There were no differences in nephrotoxicity between groups (p = 0.521). The addition of EGNAP to the antibiotic prophylactic protocol prior to TKA had no effect on overall or Gram-negative PJI risk in TKA patients. The findings of this study suggest that while EGNAP is safe to use and has minimal nephrotoxic effects, its prophylactic benefits do not extend to the primary TKA population. This may be attributed to the generally low rate of Gram-negative infections in TKA patients, where adding EGNAP does not provide a clear advantage in reducing the risk of such infections, unlike its potential benefits in primary THA population. This study investigates the effects of using prophylactic Gram-negative antibiotics prior to TKA and shows that though it is safe to use, Gram-negative bacterial coverage may have no impact on postoperative infection incidence.

BACKGROUND:Robotic assistance (RA) is increasingly used in total knee arthroplasty (TKA) for more accurate bony resection and balancing. However, the impact of robotic TKA (RATKA) on clinical outcomes and patient-reported measures (PROMs) remains unclear. This study aims to compare RATKA and conventional TKA (CTKA) using a novel robotic system. METHODS:A retrospective review was conducted on 10,031 patients who underwent TKA from February 2021 to October 2024. 289 RATKAs were performed with a hand-held robotic system. These RATKA cases were 1:1 propensity-score matched to CTKA for patient demographics, surgeon, implant system, and articulation design. Postoperative and clinical outcomes including surgical time, length of stay (LOS), discharge disposition, 90-day emergency department (ED) visits, manipulation under anesthesia (MUA), debridement, reoperations and revisions were collected and analyzed. Patient-reported outcomes measures (PROMs) included Knee Injury and Osteoarthritis Outcome Scores (KOOS, JR) and Patient Reported Outcome Measurement Information System (PROMIS) scores. RESULTS:RATKA demonstrated significantly shorter LOS (30.04 vs. 51.91 hours, p < 0.001, respectively) compared to CTKA. There was no difference in surgical time (107.18 vs. 106.22 minutes, p = 0.349). Although there was no statistical difference in 90-day ED visits, the majority of the CTKA revisits were due to surgery-related causes when compared to the RATKAs (1.38% vs. 0.34%, p = 0.239). While RATKAs had higher incidence of MUAs (2.07% vs. 0.34%, p = 0.201), CTKAs had more reoperations (1 vs. 0, p = 0.369) and more revisions than the RATKAs (6 vs. 0, p = 0.117). In terms of PROMs, both RATKAs and CTKAs showed similar improvements in KOOS, JR and PROMIS pain scores following TKA, with no significant differences in the magnitude of improvement at early postoperative timepoints. However, at the one-year follow-up, RATKA demonstrated significantly greater reduction in PROMIS pain intensity (Δ-9.12, p = 0.032) compared to CTKAs. CONCLUSIONS:This retrospective analysis showed that the novel RATKA resulted in reduced length of stay, fewer reoperations, and greater reduction in one-year PROMIS pain intensity compared to CTKAs, despite having a higher incidence of MUA rates. Further research is needed to clarify these differences clinically and enhance patient outcomes.