Search

Background: Utilizing conversational analytics in orthopaedic surgery may provide insights into patients' experiences and outcomes. This study retrospectively assessed how patients interacted with a perioperative chatbot and whether the topic of patients' queries could offer insight on their outcomes after total knee or hip arthroplasty., Methods: We identified 1338 patients (746 knees and 592 hips) who enrolled in a short message service chatbot from 2020-2022 with greater than 3 months of follow-up. The total number and topics of patient-generated text responses to the chatbot were recorded. Independent t -tests, chi-squared tests, and linear regressions were performed to determine if specific patient-generated responses to the chatbot or overall chatbot engagement were associated with demographics or outcomes., Results: Readmitted patients interacted less with the perioperative chatbot than those who were not readmitted (3.9 messages vs 12.7 messages, P < .0001). Return to emergency department (ED) and reoperation rates were not associated with engagement. Patients who visited the ED within 90 days of their surgery were most commonly seeking advice about walking after surgery ( P  = .0046) and weaning off their opiate pain medications ( P  = .0281). Patients who were readmitted to the hospital were similarly seeking advice about walking ( P  = .0188) and weaning off pain medications ( P  = .0218). Replying "exercise" was associated with no ED visits or readmissions ( P  = .0009). Patients with a mental health diagnosis were more likely to reply with high-acuity topics ( P  = .0052)., Conclusions: The topic of chatbot queries and chatbot engagement were associated with patient outcomes after total knee arthroplasty or total hip arthroplasty and may provide insight to patients' perioperative courses., (© 2024 The Authors.)

Background: Prior open reduction and internal fixation (ORIF) of tibial plateau fracture (TPF) adds complexity to subsequent total knee arthroplasty (TKA). The purpose of this study was to compare the outcomes of patients undergoing a TKA following prior ORIF of TPF to patients undergoing a primary TKA for osteoarthritis and an aseptic revision TKA., Methods: There were 52 patients who underwent primary TKA following prior ORIF of TPF between January 2009 and June 2021, who were included and matched in a 1:4 ratio to 208 patients undergoing primary TKA. A second 1:1 matched comparison to 52 aseptic revision TKA patients was also included. The Knee injury and Osteoarthritis Outcome Score for Joint Replacement scores were obtained preoperatively and at two years postoperatively. Independent t-tests and Chi-square tests were used for statistical comparisons., Results: The TPF patients were significantly younger than both primary and revision cohorts (55 ± 14.0 versus 63 ± 16.3 versus 64 ± 9.5, P < 0.001). Compared to primary TKA patients, the TPF group had worse Knee injury and Osteoarthritis Outcome Score for Joint Replacement scores at two years (46.9 ± 18.5 versus 66.2 ± 17.8, P = 0.0152), higher rates of wound complications (15.4 versus 3.9%, P = 0.0020), and increased operative times (140.2 ± 45.3 versus 95.2 ± 25.7, P < 0.0001). Additionally, TPF patients were more likely to require a manipulation under anesthesia than both primary and revision patients (21.2 versus 5.8 versus 5.8%, P = 0.001)., Conclusions: The TKAs following ORIF of TPF are more like revision TKAs than primary TKAs in terms of patient-reported outcomes, operative times, and wound complications. The rate of manipulation under anesthesia was higher than in both matched groups. These findings provide valuable information that can affect preoperative patient education and postoperative management regimens. They also emphasize the need for a conversion TKA code due to increased complexity and complications seen in this more difficult subset of TKAs., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Unanticipated failure to discharge home (failure to launch, FTL) following scheduled same-day discharge (SDD) total joint arthroplasty (TJA) is problematic for the surgical facility with respect to staffing, care coordination, and reimbursement concerns. The aim of this study was to review rates, etiologies, and contributing factors for FTL in SDD TJA at an inpatient academic medical center., Methods: All patients who underwent primary TJA between February 2021 and February 2023 were retrospectively reviewed. Of those scheduled for SDD, risk factors for FTL were compared with successful SDD. Readmission and emergency department (ED) visits were compared with historical cohorts. There were 3,093 consecutive primary joint arthroplasties performed, of which 2,411 (78%) were scheduled for SDD., Results: Overall, SDD was successful in 94.2% (n = 2,272) of patients who had an FTL rate of 5.8%. Specifically, SDD was successful in 91.4% with total hip arthroplasty, 96.0% with total knee arthroplasty, and 98.6% with unicompartmental knee arthroplasty. Factors that significantly increased the risk of FTL included general anesthesia versus spinal anesthesia (P < .0001), later surgery start time (P < .0001), longer surgical time (P = .0043), higher estimated blood loss (P < .0001), women (P = .0102), younger age (P = .0079), and lower preoperative mental health patient-reported outcomes scores (P = .0039). Readmission and ED visit rates were not higher in the SDD group when compared to historical controls (P = .6830)., Conclusions: With a comprehensive multidisciplinary approach dedicated to improving SDDs at an academic medical center, we have seen successful SDD in nearly 80% of primary TJA, with an FTL rate of 5.8%, and no increased risk of readmission or ED visits. Without adding many personnel, hospital recovery units, or other resources, simple interventions to help decrease FTL have included enhanced preoperative education and expectation settings, improved perioperative communications, reallocating personnel from the inpatient to the outpatient setting, the use of short-acting spinal anesthetics, and earlier scheduled surgery times., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Periprosthetic joint infection is a devastating complication of total knee arthroplasty and is often treated with 2-stage revision. We retrospectively assessed whether replacing the patellar component with articulating stage-one spacers was associated with improved outcomes compared to spacers without patellar component replacement., Methods: A total of 139 patients from a single academic institution were identified who underwent an articulating stage-one revision total knee arthroplasty and had at least 1-year follow-up. Of the 139 patients, 91 underwent patellar component removal without replacement, while 48 had a patellar component replaced at stage-one revision. Patellar fracture and reinfection at any point after stage-one were recorded. Knee range of motion (ROM), patellar thickness, lateral tilt, and lateral displacement were measured at 6-weeks post stage-one. Chi-square, Fisher's exact, and t-tests were utilized for comparisons. There were no significant demographic differences between groups., Results: Patellar component replacement at stage-one revision was associated with fewer patellar fractures (2.1 versus 12.1%, P = .046), less lateral patellar displacement (1.7 versus 16.0 mm, P < .01), and improved pre to postoperative knee ROM 6 weeks after stage-one (+5.9 versus -11.4°, P = .03). There was no difference in reinfections after stage-2 revision for the replaced or unreplaced patellar groups (15.4 versus 15%, P = 1.000). While the mean time between stage-one and stage-2 was not different (5.2 versus 4.5 months, P = .50), at one-year follow-up, significantly more patients in the patellar component replacement group were satisfied and refused stage-2 revision (45.8 versus 3.3%, P < .001)., Conclusions: Replacing the patellar component at stage-one revision is associated with a decreased rate of patellar fracture and lateral patellar subluxation, improved ROM, and possible increased patient satisfaction, as reflected by nearly half of these patients electing to keep their spacer. There was no difference in reinfection rates between the cohorts., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Vancomycin and tobramycin have traditionally been used in antibiotic spacers. In 2020, our institution replaced tobramycin with ceftazidime. We hypothesized that the use of ceftazidime/vancomycin (CV) in antibiotic spacers would not lead to an increase in treatment failure compared to tobramycin/vancomycin (TV)., Methods: From 2014 to 2022, we identified 243 patients who underwent a stage I revision for periprosthetic joint infection. The primary outcome was a recurrent infection requiring antibiotic spacer exchange. We were adequately powered to detect a 10% difference in recurrent infection. Patients who had a prior failed stage I or two-stage revision for infection, acute kidney injury prior to surgery, or end-stage renal disease were excluded. Given no other changes to our spacer constructs, we estimated cost differences attributable to the antibiotic change. Chi-square and t-tests were used to compare the two groups. Multivariable logistic regressions were utilized for the outcomes., Results: The combination of TV was used in 127 patients; CV was used in 116 patients. Within one year of stage I, 9.8% of the TV group had a recurrence of infection versus 7.8% of the CV group (P = .60). By final follow-up, results were similar (12.6 versus 8.6%, respectively, P = .32). Adjusting for potential risk factors did not alter the results. Cost savings for ceftazidime versus tobramycin are estimated to be $68,550 per one hundred patients treated., Conclusions: Replacing tobramycin with ceftazidime in antibiotic spacers yielded similar periprosthetic joint infection eradication success at a lower cost. While larger studies are warranted to confirm these efficacy and cost-saving results, our data justifies the continued investigation and use of ceftazidime as an alternative to tobramycin in antibiotic spacers., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Same-day discharge (SDD) after total joint arthroplasty (TJA) is safe and cost effective. However, benefits may be offset by the potential cost of emergency department (ED) visits and readmissions. We identified risk factors for return to the ED and readmission in patients who underwent SDD and inpatient (IP) stays after TJA., Methods: We performed a retrospective review of patients who underwent primary TJA at an academic institution over the course of one year. There were 1,708 consecutive TJAs (721 THA [total hip arthroplasty] and 987 TKA [total knee arthroplasty]) included. A SDD occurred after 1,199 (70%) TJAs, 523 THAs, and 676 TKAs. We compared the demographics and comorbidities of patients who have SDD or IP who stayed following TJA. We documented rates of return to the ED or readmission within 90 days of surgery. Cohorts were compared using the Student's t-test or Chi-square test. Significant findings were those with P value < .05., Results: The SDD cohort had a significantly higher rate of young, non-White men who had a lower body mass index and fewer comorbidities than the IP cohort. Rates of return to ED and readmission were similar between SDD and IP cohorts after TJA and similar between THA and TKA. Factors that significantly influenced return to ED included a higher American Society of Anaesthesiologists score (SDD, IP), a higher Charlson Comorbidity Index score (SDD, IP), a lower body mass index (IP), and a psychological diagnosis (SDD, IP). Factors that significantly influenced readmission rates included a higher American Society of Anaesthesiologists score (SDD), older age (SDD), and psychological diagnosis (SDD, IP)., Conclusions: Patients who discharged the same day after primary TJA have similar rates of return to the ED and readmission as those admitted as an IP. Patients who had a psychological diagnosis, and particularly a diagnosis of depression, are at higher risk for return to the ED and readmission after primary TJA, regardless of discharge the same-day or IP admission. Improved measures that attempt to further treat and optimize this patient population could reduce unnecessary postoperative ED visits., (Copyright © 2024. Published by Elsevier Inc.)

Modern highly porous surfaces have increased confidence and use of cementless total knee arthroplasty (TKA) in the United States. As cementless TKA use increases, there remains a paucity of literature regarding associated risk of revision in patients aged ≥65 years. We analyzed the American Joint Replacement Registry (AJRR) data from January 2012 to March 2020 identifying patients aged ≥65 years undergoing primary TKA with linked cases to supplemental centers for Medicare and Medicaid data. Patients with hybrid fixation, reverse hybrid fixation, missing component data, highly constrained implants, and stem extension/augmentation were excluded. We identified 442,745 cemented TKAs and 19,841 modern cementless TKAs with a minimum of 2-year follow-up. Cumulative incident function (CIF) curves and cause-specific Cox models evaluated the risk of all-cause revision and revision for mechanical loosening, adjusting for body mass index (BMI), sex, age, cruciate retaining (CR) versus posterior stabilized (PS) femoral design, patellar resurfacing, and Charlson's comorbidity index (CCI). Patients with cementless compared with cemented TKA were younger (mean age: 71.9 vs. 73.2 years, p  < 0.001), more likely to be male sex (48.8 vs. 39.0%, p  < 0.001), more likely to have a CR femoral design (81.1 vs. 45.7%, p  < 0.001), less likely to have patellar resurfacing (92.7 vs. 95.0%, p  < 0.001), and had a lower CCI (mean: 2.9 vs. 3.1, p  < 0.001). Adjusted hazard ratios (HRs) showed no difference in associated risk for all-cause revision (HR: 1.07; 95% confidence interval [CI]: 0.92-1.24; p  = 0.382) or revision for mechanical loosening (HR: 1.38; 95% CI: 0.9-2.12; p  = 0.14) for cementless versus cemented TKA. Our results suggest that current selective use of cementless fixation for TKA in patients aged ≥65 years in the United States is not associated with an increased risk of revision. While encouraging, further study is necessary to establish indications for use in this age group prior to broader adoption in this patient population. LEVEL OF EVIDENCE:  Therapeutic Level III., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Several patient factors affect recovery after total hip arthroplasty (THA). However, the impact of these variables on patient-reported outcome measure recovery curves following THA has not been defined. Our goal was to quantify the influence of multiple variables on recovery after primary THA., Methods: There were 1,724 patients in a multicenter study included. Variables included sex, race/ethnicity, anxiety/depression, body mass index, tobacco, and preoperative opioid use. The Hip disability and Osteoarthritis Score for Joint Replacement (HOOS JR) was recorded at multiple time points. Recovery curves were created using longitudinal estimating equations., Results: Patients who were women, obese, or smokers demonstrated lower HOOS JR scores at all time points. Preoperative opioid use was also correlated with lower HOOS JR scores, but this difference diminished after 6 months. Black patients demonstrated lower HOOS JR scores compared to Caucasians, and this relative difference increased out to 1-year postoperatively (P = .018). Hispanics also had lower HOOS JR scores, but scores recovered at similar rates compared to non-Hispanics. Patients who had only anxiety or depression had similar HOOS JR scores compared to patients who did not have anxiety or depression. However, patients who had both anxiety and depression had lower HOOS JR scores compared to patients who had neither (P = .049), and this relative difference became greater at 1-year postoperatively (P = .002)., Conclusions: Several factors including race/ethnicity, opioid use, and mental health influence recovery trajectory following THA. This information helps provide more individualized counseling about expectations after THA and focus targeted interventions to improve outcomes in at-risk groups., (Copyright © 2023. Published by Elsevier Inc.)

Background: Instability is a known complication following total hip arthroplasty (THA) and is influenced by spinopelvic alignment. Radiographic markers have been investigated to optimize the acetabular cup position. This study evaluated if the empty ischial fossa (EIF) sign and the position of the trans-teardrop line were predictive of postoperative instability., Methods: All patients who underwent THA from 2011 to 2018 at a single institution were retrospectively reviewed. Pelvic tilt was measured using a trans-teardrop line compared to the superior aspect of the pubic symphysis on standing anteroposterior pelvis radiographs. Postoperative dislocations were identified through chart review and radiographic review. The EIF sign was determined by the presence of uncovered bone below the posterior inferior edge of the acetabular component at the level of the native ischium and posterior wall on standing postoperative anteroposterior radiographs., Results: One thousand seven hundred fifty patients (952 anterior approach and 798 posterior approach) were included. The EIF sign was present in 458 patients (26.2%) and associated with an increased dislocation rate (3.9% vs 0.9%, P < .0001). Patients with spondylosis/instrumented fusion, and positive EIF sign had a dislocation risk of 5.1% vs 1.3% ( P  = .001). A postoperative outlet pelvis was not significant for increased dislocation risk (odds ratio 2.16, P  = .058). Patients with combined spondylosis/fusion, posterior approach, outlet pelvis, and EIF sign had a dislocation rate of 14.5%., Conclusions: The EIF sign was an independent risk factor for postoperative instability and may represent failure to account for pelvic tilt. Avoidance of the EIF sign during cup positioning may help reduce dislocations following THA., (© 2023 Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons.)

Background: Antibiotic-loaded bone cement (ALBC) is commonly used in the treatment of periprosthetic joint infections (PJIs) to increase the local concentration of antibiotic at the site of infection. Use of ALBC has been associated with rare instances of acute kidney injury (AKI) despite low systemic absorption of the nephrotoxic antibiotics; however, the incidence of AKI is unknown. The purpose of this study was to determine the incidence of and risk factors for AKI associated with ALBC., Methods: This single-site, retrospective cohort study compared 162 PJI patients who underwent Stage 1 revision to a spacer with ALBC to 115 PJI patients who underwent debridement, antibiotics, and implant retention (DAIR) without the use of ALBC. Both groups received similar systemic antibiotics postoperatively. Descriptive statistics and multivariable logistic regressions were used to analyze risk factors for AKI., Results: There was no statistically significant difference in the rate of AKI: 29 patients (17.9%) in the ALBC group and 17 (14.7%) in DAIR group developed AKI (odds ratio 1.43; 95% CI 0.70 to 2.93). There was a trend toward increased severity of AKI in the ALBC group. Chronic kidney disease, systemic vancomycin, and diuretic use were independent factors associated with the risk of AKI., Conclusion: An AKI occurred in 17% of PJI patients receiving either a spacer with ALBC or a DAIR. The use of ALBC was not associated with a significant increased risk of AKI. However, the use of systemic vancomycin and diuretic use were independent predictors of AKI in this patient population., (Published by Elsevier Inc.)

Purpose: Primary purpose was to identify relationships between performance-based measures onto both computerized adaptive testing [Physical Function-Computer Adaptive Testing (PF-CAT)] and joint-specific legacy [Knee injury and Osteoarthritis Outcome Score-Activities of Daily Living (KOOS-ADL)] instruments pre- and 12-month post-TKA., Methods: The PF-CAT and KOOS-ADL were identified as outcomes and performance on the 40-m fast-paced walking test, stair climb test and chair stand test were identified as predictors. Linear regression was used for all comparisons after adjusting for confounders., Results: Sixty-eight people with TKA (56.7% male) were tested. Better scores on the 40-m fast-paced walking (KOOS-ADL, p  = 0.02), stair climb (KOOS-ADL, p  = 0.05) and chair stand (KOOS-ADL, p  < 0.01) associated with better self-reported scores pre-TKA. Better scores on the 40-m fast-paced walking (PF-CAT, p  = 0.05; KOOS-ADL, p  = 0.01), stair climb (KOOS-ADL, p  < 0.01), chair stand (PF-CAT, p  < 0.01) and range of motion (KOOS-ADL, p  = 0.02) were associated with better self-reported scores 12-month post-TKA. Decrease knee range of motion related to poorer 40-m fast-paced walking ( p  = 0.01) and stair climb ( p  = 0.03) scores pre-TKA. Quadriceps weakness related to poorer 40-m fast-paced walking ( p  = 0.04) score pre-TKA., Conclusion: Self-reported instruments are a moderate, but inconsistent surrogate to performance-based measures pre- and post-TKA. Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the recovery analysis of people undergoing TKA.Implications for RehabilitationMonitoring the trajectory of pre- to post-total knee arthroplasty (TKA) physical function is important as it directly relates to mortality, morbidity and poorer quality of life in older adults.Both self-reported and performance-based measures of physical function are used to determine progress in recovery for patients pre- and post- TKA.This study provides evidence that perceived physical function measures are a moderate, but an inconsistent, surrogate to objective physical function measures pre- and post-TKA.Joint specific deficits in knee range of motion and quadriceps strength were weakly associated with deficits in function measures pre-TKA, but no association was observed 12-month post-TKA.Our findings indicate that both self-reported and performance-based measures are necessary to fully characterize physical function and should be used jointly to aid in the complete recovery analysis of people undergoing TKA.

Background: Aseptic loosening following total knee arthroplasty remains one of the leading causes of long-term failure. Radiographic identification of loose implants can be challenging with standard views. The purpose of this study was to compare the incidence of novel radiographic findings of anterior heterotopic bone formation and medial or lateral cyst formation in patients who have aseptic loosening to patients who have well-fixed implants., Methods: A retrospective radiographic review was performed on 48 patients' revised secondary to aseptic tibial loosening. This cohort was compared to two additional cohorts; 48 patients returning for routine postoperative follow-up (control 1), and 48 patients revised secondary to infection or instability who had well-fixed implants (control 2)., Results: There were 41 of 48 (85%) patients who had implant loosening and were noted to have anterior heterotopic bone formation compared to 1 of 48 (2%) patients in control 1 and 3 of 48 (6%) patients in control 2 (P ≤ .0001). There were 43 of 48 (90%) patients who had implant loosening and had medial cyst formation compared to 3 of 48 (6%) patients in control 1 and 5 of 48 (10%) in control 2 (P ≤ .0001). There were 42 of 48 (88%) patients who had implant loosening and had lateral cyst formation compared to 2 of 48 (4%) patients in control 1 and 4 of 48 (8%) in control 2 (P ≤ .0001)., Conclusion: In this study, we describe novel radiographic findings of anterior heterotopic bone formation and cysts that develop in patients who have aseptic loosening following primary total knee arthroplasty. We believe that these radiographic features may lead to easier identification of aseptic loosening., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Patient-reported outcome measures (PROMs) are frequently used for evaluating patient satisfaction and function following total hip arthroplasty (THA). Functional measures along with chronologic modeling may help set expectations perioperatively. Our goal was to define the trajectory of recovery and function in the first year following THA., Methods: Prospective data from 1,898 patients in a multicenter study was analyzed. The PROMs included the Hip disability and Osteoarthritis Score for Joint Replacement and EuroQol-5 dimension. Physical activity was recorded on a wearable technology. Data was collected preoperatively and at 1, 3, 6, and 12 months postoperatively. Generalized estimating equations were used to evaluate outcomes over time., Results: Significant improvement occurred between preoperative and postoperative time points for all PROMs. The PROMs showed the greatest proportional recovery within the first month postoperatively, each improving by at least 1 minimal clinically important difference (MCID). Daily steps and flights of stairs took longer to reach at least 1 MCID (3 months and 1 year, respectively). Gait speed and walking asymmetry returned to baseline by 3 months, but did not reach a MCID of improvement by 1 year., Conclusion: Patients can be counseled that the greatest proportional improvement in PROMs is within 1 month after THA, while function surpasses preoperative baselines by 3 months, and gait quality may not improve until after 1 year. This can help set realistic expectations and target interventions toward patients deviating from the norm., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Aseptic loosening persists as one of the leading causes of failure following cemented primary total knee arthroplasty (TKA). Cement technique may impact implant fixation. We hypothesized that there is variability in TKA cement technique among arthroplasty surgeons., Methods: A 28-question survey regarding variables in surgeons' preferred TKA cementation technique was distributed to 2,791 current American Association of Hip and Knee Surgeons (AAHKS) members with a response rate of 30.8% (903 respondents). Patterns of responses were analyzed by grouping respondents by their answers to certain questions including cementing technique, tibial cement location, and femoral cement location., Results: A total of 73.5% reported performing at least 7 of 8 of the highest consensus techniques, including vacuum mixing (79.9%), using two bags (76.1%), tibial implant first (95.2%), single-stage cementing (96.9%), compression of the implants in extension (91.7%), and use of a tourniquet (84.3%). Medium and high viscosity cement was most commonly used (37.9 and 37.8%, respectively). Finger pressurization was most common (76.1%) compared to a gun (29.8%). There were 26.5% of respondents performing 6 or fewer of the most common majority techniques and seemed to perform other less common techniques (eg, use of a single bag of cement, trialing or closure prior to cement curing, and heating to accelerate cement curing). Cement was most commonly applied to the entire bone and implant surface on both the tibia (46.4%) and femur (47.7%), leaving much variation in the remaining cement application location responses., Discussion: There appears to be variability in cemented TKA technique among arthroplasty surgeons. There were 26.5% of respondents performing less of the majority techniques and also performed other additional low-response rate techniques. Further studies that look at the impacts of variation in techniques on outcomes may be warranted. Our study demonstrates the need for defining best practices for cement technique given the substantial variability identified., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Mobile-bearing (MB) total knee arthroplasty (TKA) may reduce wear and improve patellar tracking but may increase revision risk due to tibial component design, balance complexity, and bearing dislocation. We utilized the American Joint Replacement Registry to examine risk of revision with MB compared to fixed-bearing (FB) designs., Methods: An analysis of primary TKA in patients over 65 years was performed with American Joint Replacement Registry data linked to Centers for Medicare and Medicaid Services data from 2012 to 2019. Analyses compared MB to FB designs with a subanalysis of implants from a single company. We identified 485,024 TKAs, with 452,199 (93.2%) FB-TKAs and 32,825 (6.8%) MB-TKAs. Cox proportional hazards regression modeling was used for all-cause revision and revision for infection, adjusting for sex, age, and competing risk of mortality. Event-free survival curves evaluated time to all-cause revision and revision for infection., Results: MB-TKAs were at an increased risk for all-cause revision: hazard ratio (HR) 1.36 ([95% confidence interval (CI) 1.24-1.49], P < .0001) but not revision for infection: HR 1.06 ([95% CI 0.90-1.25], P = .52). When comparing implants within a single company, MB-TKAs were at an increased risk of all-cause revision: HR 1.55 ([95% CI 1.38-1.73], P < .0001). Event-free survival curves demonstrated increased risk for all-cause revision for MB-TKA across all time points, with a greater magnitude of risk up to 8 years., Conclusion: Although survivorship of both designs was outstanding, MB-TKA designs demonstrated increased risk for all-cause revision. Additional investigation is needed to determine if this is related to patient selection factors, surgical technique, bearing, or implant design., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Outcomes of patellofemoral arthroplasty (PFA) to total knee arthroplasty (TKA) conversion are reported to be similar to primary cases. The purpose of this study was to determine whether the cause for conversion from PFA to TKA correlated to outcomes when compared to a matched cohort., Methods: A retrospective chart review was performed to identify aseptic PFA to TKA conversions between 2000 and 2021. A cohort of primary TKAs was matched by patient sex, body mass index, and American Society of Anesthesiology score. Clinical outcomes, including range of motion, complication rates, and patient reported outcomes measurement information systems scores, were compared. Chi-squared, Fisher's Exact, and t-tests were performed. There were 20 PFA to TKA conversions that met inclusion criteria and were matched to 60 primary cases., Results: There were 7 cases revised for arthritis progression, 5 for femoral component failure, 5 for patellar component failure, and 3 for patellar maltracking. PFA to TKA conversions for patellar failure (fracture, component loosening) had worse postoperative flexion (115 versus 127°, P = .023) and more complications of stiffness (40 versus 0%, P = .046) than primary TKAs. Conversions for failed patellar components had worse patient reported outcomes measurement information systems physical function (32 versus 45, P = .0046), physical health (42 versus 49, P = .0258), and pain scores (45 versus 24, P = .0465). No differences were found in rates of infection, manipulations under anesthesia, or reoperations., Conclusion: PFA to TKA conversion outcomes were similar to primary TKA, except in patients who had failed patellar components and demonstrated worse postoperative range of motion and patient-reported outcomes. Surgeons should avoid thin patellar resections and extensive lateral releases to minimize patellar failures., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Extensor mechanism disruption (EMD) following total knee arthroplasty (TKA) is a devastating problem commonly treated with allograft or synthetic reconstruction. Understanding of reconstruction success rates and patient recorded outcomes is lacking., Methods: Patients who have an EMD after TKA undergoing mesh or whole-extensor allograft reconstruction between 2011 and 2019, with minimum 2-year follow-up were reviewed at two tertiary care centers. Functional failure was defined as extensor lag >30 degrees, amputation, or fusion, as well as revision extensor mechanism reconstruction (EMR). Survivorship was assessed using Kaplan-Meier curves, and factors for success were determined with logistic regressions., Results: Of fifty-six EMRs (49 patients), 50.0% (28/56) were functionally successful at 3.2 years of mean follow-up (range, 0.2 to 7.4). In situ survivorship of the reconstructions at 36 months was 75.0% (42 of 58). There were 50.0% (14 of 28) of functionally failed EMRs that retained their reconstruction at last follow-up. Mean extensor lag among successes and failures was 5.4 and 71.0° (P = .01), respectively. Mean Knee Injury and Osteoarthritis Outcome Score, Joint Replacement scores were 67.1 and 48.8 among successes and failures (P = .01). There were 64.0% (16 of 25) of successes and 1 of 19 failures that obtained a Knee Injury and Osteoarthritis Outcome Score, Joint Replacement score above the minimum patient-acceptable symptom state for TKA. Survivorship and success rates were similar between reconstruction methods (P = .86; P = .76). All-cause mortality was 8.2% (4 of 49), each with EMR failure prior to death. All-cause reoperation rate was 42.9% (24 of 56), with a 14.3% (8 of 56) rate of revision EMR and 10.7% (6 of 56) rate of above-knee-amputation or modular fusion., Conclusions: This multicenter investigation of mesh or allograft EMR demonstrated modest functional success at 3.2 years. Complication and reoperation rates were high, regardless of EMR technique. Therefore, EMD after TKA remains problematic., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: This study aimed to describe the trajectory of recovery based on patient-reported outcomes (PROs) and objective metrics of physical activity measures over the first 12 months post-total knee arthroplasty (TKA)., Methods: In total, 1,005 participants who underwent a primary unilateral TKA surgery between November 2018 and September 2021 from a multisite prospective study were analyzed. Generalized estimating equations were used to evaluate PROs and objective physical activity measures over time., Results: All Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), EuroQol-5D (EQ-5D), and steps per day scores were greater than preoperative scores (P < .05). The flights of stairs per day, gait speed, and walking asymmetry all declined at 1 month (all, P < .001). However, all subsequent scores improved by 6 months (all, P < .01). The greatest clinically important differences from previous visit in KOOS JR (β = 18.1; 95% Confidence Interval (CI) = 17.2, 19.0), EQ-5D (β = 0.11; 95% CI = 0.10, 0.12), steps per day (β = 1,169.3; 95% CI = 1,012.7, 1,325.9), gait speed (β = -0.05; 95% CI = -0.06, -0.03), and walking asymmetry (β = 0.00; 95% CI = -0.03, 0.03) were observed at 3 months., Conclusion: The KOOS JR, EQ-5D, and steps per day measures showed earlier improvements than other physical activity metrics, with the greatest magnitude of improvement within the first 3 months post-TKA. The greatest magnitude of improvement in walking asymmetry was not observed until 6 months, while gait speed and flights of stairs per day were not observed until 12 months. This data may further help provide expectation setting information to patients before surgery, and may aid in identifying outliers to the normal recovery curve who may benefit from targeted interventions., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Functional patient-specific acetabular component positioning is important in total hip arthroplasty. We preoperatively evaluate the pelvic tilt (PT) on standing anteroposterior (AP) pelvis radiographs using a novel measurement and then recreate this intraoperatively using imaging. The purpose of this study was to determine if there is a linear correlation between this novel measurement and the actual PT., Methods: A retrospective study of 200 patients was performed, measuring PT on standing lateral radiographs as the angle between the anterior superior iliac spines and the pubic symphysis. On the AP pelvis radiographs, the trans-teardrop (TT) line was drawn between the teardrops. The vertical distance between the TT line and the top of the pubic symphysis (TTPS) was then measured. A ratio was made between the lengths of both lines to account for the overall size of the pelvis (TTPS/TT). Linear regression analysis was then performed between PT and TTPS/TT., Results: There was a strong linear correlation between the TTPS/TT ratio on AP pelvis radiographs and PT on lateral radiographs (r = 0.785, r 2  = 0.616, P < .001). On subanalysis of the female cohort, the correlation became even stronger (r = 0.864, r 2  = 0.747, P < .001). Using regression analysis, a linear equation was created (PT = 97.32 [TTPS/TT] - 5.51), to calculate the PT using the TTPS/TT ratio., Conclusions: There is a strong linear correlation between the TTPS/TT ratio and PT. Using this information, a surgeon can reliably use the distance between the TT line and the superior pubic symphysis on an AP radiograph to recreate the patient's functional PT intraoperatively, allowing for a more accurate patient-specific placement of the acetabular component., (© 2023 The Authors.)

Background: Recent advances in high-throughput DNA sequencing technologies have made it possible to characterize the microbial profile in anatomical sites previously assumed to be sterile. We used this approach to explore the microbial composition within joints of osteoarthritic patients., Methods: This prospective multicenter study recruited 113 patients undergoing hip or knee arthroplasty between 2017 and 2019. Demographics and prior intra-articular injections were noted. Matched synovial fluid, tissue, and swab specimens were obtained and shipped to a centralized laboratory for testing. Following DNA extraction, microbial 16S-rRNA sequencing was performed., Results: Comparisons of paired specimens indicated that each was a comparable measure for microbiological sampling of the joint. Swab specimens were modestly different in bacterial composition from synovial fluid and tissue. The 5 most abundant genera were Escherichia, Cutibacterium, Staphylococcus, Acinetobacter, and Pseudomonas. Although sample size varied, the hospital of origin explained a significant portion (18.5%) of the variance in the microbial composition of the joint, and corticosteroid injection within 6 months before arthroplasty was associated with elevated abundance of several lineages., Conclusions: The findings revealed that prior intra-articular injection and the operative hospital environment may influence the microbial composition of the joint. Furthermore, the most common species observed in this study were not among the most common in previous skin microbiome studies, suggesting that the microbial profiles detected are not likely explained solely by skin contamination. Further research is needed to determine the relationship between the hospital and a "closed" microbiome environment. These findings contribute to establishing the baseline microbial signal and identifying contributing variables in the osteoarthritic joint, which will be valuable as a comparator in the contexts of infection and long-term arthroplasty success., Level of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/H489)., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: The Center for Medicare and Medicaid Innovation revised the comprehensive Care for Joint Replacement (CJR) program, a mandatory 90-day bundled payment for lower extremity joint replacement, in December 2017, retaining 34 of the original 67 metropolitan statistical areas with higher volume and historic episode payments., Objectives: We describe differences in costs, quality, and patient selection between hospitals that continued to participate compared with those that withdrew from CJR before and after the implementation of CJR., Research Design: We used a triple difference approach to compare the magnitude of the policy effect for elective admissions between hospitals that were retained in the CJR revision or not, before and after the implementation of CJR, and compared with hospitals in nonparticipant metropolitan statistical areas., Subjects: 694,275 Medicare beneficiaries undergoing elective lower extremity joint replacement from January 1, 2013 to August 31, 2017., Measures: The treatment effect heterogeneity of CJR., Results: Hospitals retained in the CJR policy revision had a greater reduction in 90-day episode-of-care cost compared with those that were allowed to discontinue (-$846, 95% CI: -$1,338, -$435) and had greater cost reductions in the more recent year (2017). We also found evidence that retained CJR hospitals disproportionately reduced treating patients who were older than 85 years., Conclusions: Hospitals that continued to participate in CJR after the policy revision achieved a greater cost reduction. However, the cost reductions were partly attributed to avoiding potential higher - cost patients, suggesting that a bundled payment policy might induce disparities in care delivery., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Existing studies of patient-reported outcomes (PRO) following total knee arthroplasty (TKA) based on fixation methods (cemented vs cementless) are limited to single centers with small sample sizes. Using multicentered data,, we compared baseline and early post-operative global and condition-specific PROs between patients undergoing cemented versus cementless TKA., Methods: With PROs prospectively collected through Comparative Effectiveness Pulmonary Embolism Prevention After Hip and Knee Replacement (PEPPER) trial (ClinicalTrials.gov: NCT02810704), we examined pre- and post-operative (1, 3, and 6-months) outcomes in 5,961 patients undergoing primary TKA enrolled by 28 medical centers between December 2016 and August 2021. Outcomes included the short-form of the Knee Injury and Osteoarthritis Outcome Score (KOOS-Jr.), the Patient-Reported Outcomes Measurement Information System Physical Health (PROMIS-PH), and the Numeric Pain Rating Scale (NPRS). To minimize selection bias, we performed a 1-to-1 propensity score matched analysis to assess relative pre- to post-operative change in outcomes within and between cemented and cementless TKA groups., Results: With greater than 90% follow-up, significant pre to- post-operative improvements were observed in both groups. At 6 months, the cemented TKA group achieved a 3.3 point (55% of the Minimum Clinically Important Difference) greater improvement in the mean KOOS-Jr. (95%CI: 0.36, 6.30; P = 0.028) than did the cementless group with no significant between-group differences in PROMIS-PH and NPRS., Conclusions: In a large cohort of primary TKAs, patients with cemented fixation reported early incremental benefit in KOOS-Jr. over those with cementless TKA. Future studies are warranted to capture longer follow-up of PROs., (© 2022. The Author(s).)

Background: Highly cross-linked polyethylene (HXLPE) can improve wear properties in TKA, but it can also lead to decreased mechanical properties. Antioxidants were added to HXLPE to improve its mechanical properties while retaining the improved wear characteristics. However, it remains unclear whether these modifications to conventional polytheylene used in TKA have resulted in a change in the revision risk., Questions/purposes: We used American Joint Replacement Registry data to ask: (1) Is there a difference in all-cause revision in patients who underwent TKA using HXLPE with or without an antioxidant doping compared with conventional polyethylene? (2) Is there a difference in revision for aseptic failure in patients who underwent TKA using HXLPE with or without an antioxidant doping compared with conventional polyethylene?, Methods: We analyzed American Joint Replacement Registry data from 2012 to 2019. We identified 339,366 primary TKAs over the study period in patients older than 65 years and linked procedures to supplemental Centers for Medicare & Medicaid data where available. Patient total number of reported comorbidities, gender, age, region, polyethylene characteristics, procedure dates, and indication for revision were recorded. Median follow-up was 34 months. We compared HXLPE with or without antioxidants to conventional polyethylene. Event-free percent survival curves and Cox proportional hazard regression modeling was used for all-cause revision and revision for aseptic failure., Results: Compared with conventional polyethylene, there was no difference in all-cause revision with HXLPE with an antioxidant (HR 1.06 [95% CI 0.98 to 1.14]; p = 0.13) or HXLPE without an antioxidant (HR 1.04 [95% CI 0.97 to 1.11]; p = 0.28). Compared with conventional polyethylene, there was no difference in revision for aseptic failure with HXLPE with an antioxidant (HR 1.07 [95% CI 0.99 to 1.14]; p = 0.08) or HXLPE without an antioxidant (HR 1.03 [95% CI 0.97 to 1.01]; p = 0.30)., Conclusion: We found no difference in revision risk between HXLPE with or without an antioxidant and conventional polyethylene during this time frame. HXLPE polyethylene, with or without an antioxidant, should not be widely adopted until or unless it is shown to be superior to conventional polyethylene in TKA., Level of Evidence: Level III, therapeutic study., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2022 by the Association of Bone and Joint Surgeons.)

Background: The challenges of culture-negative periprosthetic joint infection (PJI) have led to the emergence of molecular methods of pathogen identification, including next-generation sequencing (NGS). While its increased sensitivity compared with traditional culture techniques is well documented, it is not fully known which organisms could be expected to be detected with use of NGS. The aim of this study was to describe the NGS profile of culture-negative PJI., Methods: Patients undergoing revision hip or knee arthroplasty from June 2016 to August 2020 at 14 institutions were prospectively recruited. Patients meeting International Consensus Meeting (ICM) criteria for PJI were included in this study. Intraoperative samples were obtained and concurrently sent for both routine culture and NGS. Patients for whom NGS was positive and standard culture was negative were included in our analysis., Results: The overall cohort included 301 patients who met the ICM criteria for PJI. Of these patients, 85 (28.2%) were culture-negative. A pathogen could be identified by NGS in 56 (65.9%) of these culture-negative patients. Seventeen species were identified as common based on a study-wide incidence threshold of 5%. NGS revealed a polymicrobial infection in 91.1% of culture-negative PJI cases, with the set of common species contributing to 82.4% of polymicrobial profiles. Escherichia coli, Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus ranked highest in terms of incidence and study-wide mean relative abundance and were most frequently the dominant organism when occurring in polymicrobial infections., Conclusions: NGS provides a more comprehensive picture of the microbial profile of infection that is often missed by traditional culture. Examining the profile of PJI in a multicenter cohort using NGS, this study demonstrated that approximately two-thirds of culture-negative PJIs had identifiable opportunistically pathogenic organisms, and furthermore, the majority of infections were polymicrobial., Level of Evidence: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H102 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Polyethylene bearing design may influence the risk of revision after total knee arthroplasty (TKA). Previous investigations from outside of the United States have suggested the potential for an increased risk of all-cause revision and revision for infection with the use of posterior-stabilized bearings. We examine the risk of revision based on the polyethylene bearing design selection for primary TKA., Methods: An analysis of the American Joint Replacement Registry (AJRR) data from 2012 to 2019 was performed. We identified all primary TKAs over the study period and linked cases to supplemental U.S. Centers for Medicare & Medicaid Services (CMS) data where available. Patient demographic characteristics, polyethylene characteristics, procedure dates, and cause for revision were recorded. Analysis was performed to compare minimally stabilized implants (cruciate-retaining, anterior-stabilized, or pivot bearing designs) with posterior-stabilized implants. Cumulative incidence function (CIF) curves and Cox proportional hazard ratios (HRs) were created for all-cause revision and revision for infection in each group., Results: We identified 305,279 cases with reported minimally stabilized or posterior-stabilized implant characteristics. There were 161,486 cases (52.9%) that utilized posterior-stabilized bearings compared with 143,793 cases (47.1%) with minimally stabilized bearings. For minimally stabilized bearings, 1,693 cases (1.18%) had all-cause revision and 334 cases (0.23%) had revision for infection. For posterior-stabilized bearings, 2,406 cases (1.49%) had all-cause revision and 446 cases (0.28%) had revision for infection. The use of posterior-stabilized bearings had HRs of 1.25 (95% confidence interval [CI], 1.2 to 1.3; p < 0.0001) for all-cause revision and 1.18 (95% CI, 1.0 to 1.4; p = 0.02) for revision for infection., Conclusions: Similar to investigations from international registries, we found an increased risk of all-cause revision and revision for infection when using posterior-stabilized bearings in TKA in the United States. Surgeons should consider this finding when considering bearing selection for primary TKA., Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H113 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: The formation of sclerotic bone, a neocortex, distally surrounding total hip arthroplasty (THA) stems may commonly be seen on radiographs around proximally porous coated stems but can be confused with loosening. The goal of this study was to determine the prevalence of the neocortex finding and whether it associated with worse outcomes after THA., Methods: A retrospective review of 825 patients with a single tapered wedge stem was performed. Radiographs at 1-year, as well as final follow-up were reviewed for evidence of sclerotic bone (neocortex) surrounding the stem in all 14 Gruen zones. The final attending radiology read of lucency was also recorded. Patients were grouped by the presence of the neocortex. PROMIS Physical Function scores and complications were compared between neocortex groups., Results: The neocortex group had 558 (68%) patients compared to 267 (32%) in the no neocortex group. The most common Gruen zones for evidence of neocortex were 10 (55%), 11 (52%), and 12 (51%). Seven percent of patients had a finding of lucency on radiology read. There was no difference between groups in terms of dislocations (P = .61), infection (P = .79), fracture rates (P = .54), revision surgery (P = .73), and reoperation for any cause (P = .62). PROMIS PF scores were significantly higher in the neocortex group (P < .0001)., Conclusion: The presence of a distal neocortex is a common finding on radiographs after THA with this proximally porous-coated tapered wedge stem and does not portend worse outcomes, nor is it a sign of aseptic loosening, increased revision rates, infection, dislocation, or periprosthetic fracture risk., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Although studies have demonstrated reductions in recurrent periprosthetic joint infection (PJI) with the administration of prolonged oral antibiotics at second-stage reimplantation, the potential for increasing bacterial resistance has not been studied. The purpose of this study was to determine if oral antibiotics at second-stage reimplantation increased the rate of antibiotic resistance in subsequent infections., Methods: We retrospectively reviewed patients who underwent 2-stage exchange for chronic PJI from 2014 to 2019. We compared those who had received prolonged oral antibiotics at the time of stage 2 reimplantation with those who did not. The primary outcome was the presence of resistant organisms in any subsequent infection. The secondary outcome was the overall rate of recurrent PJI in the 2 groups. Multivariable analyses controlling for demographics and comorbid conditions were used., Results: Of the 211 patients who underwent 2-stage exchange for PJI, 158 patients received prolonged oral antibiotics. The mean follow-up was 2.2 years. Recurrent PJI was diagnosed in 24 of 158 (15%) patients who received oral antibiotics compared with 11 of 53 (21%) patients who did not receive antibiotics (P = .35). PJI with resistant organisms was identified in 16 of 24 (67%) patients who received antibiotics compared with 0 of 11 (0%) patients who did not receive antibiotics (P = .0001)., Conclusions: Prolonged oral antibiotics following 2-stage exchange increase drug resistance to that antibiotic in subsequent PJI. We recommend further research in the area to refine antimicrobial protocols as we consider the risks and benefits of prolonged antibiotic treatment., (Published by Elsevier Inc.)

Background: Anterior-based approaches for total hip arthroplasty (THA) have gained popularity over the last decade. At our institution, anterior-based approaches are preferentially utilized, including both anterior-based muscle-sparing (ABMS) and direct anterior (DA) for primary THA. As there are higher complication rates during the transition to an anterior approach, we compared the outcomes and complications between ABMS and DA approaches beyond the learning curve., Methods: A retrospective study of all ABMS and DA primary THA patients performed at a single institution was performed, excluding the first 100 anterior cases done by any surgeon. In total, 813 DA and 378 ABMS THA cases were included. Demographics, complications, and patient-reported outcomes (PROMIS and HOOS) were obtained for each patient., Results: There was a 4.5% overall complication rate (4.1% in DA and 5.6% in ABMS, P = .248), with the most common complication being infection at 1.7% (1.5% vs 2.1%, P = .423). A revision was performed in 3.4% of cases overall (1.8% aseptic, 1.6% septic). There was no difference in complication rates between approaches. Length of surgery was shorter for ABMS (94.5 vs 116.0 minutes, P < .001). Both DA and ABMS had significant improvements in PROMIS and HOOS Jr. scores, without any significant difference between the groups., Conclusions: Anterior-based approaches for primary THA demonstrated excellent clinical results and low complication rates overall. Beyond the learning curve, excellent results can be obtained with either ABMS or DA approach for primary THA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

We report on a 34-year-old female whose normal spontaneous vaginal delivery was complicated by Group B streptococcus (GBS) colonization. She developed postpartum, bilateral, rapidly destructive septic hip arthritis. She was treated with bilateral articulating, antibiotic-impregnated spacers, 6 weeks of parenteral antibiotics, and subsequent conversion to total hip arthroplasties. In pregnant women, GBS can result in bacteremia, urinary tract infection, endometritis, and pneumonia. Less commonly, GBS can lead to endocarditis, sacroiliitis, or septic arthritis. Septic arthritis of the hip following pregnancy has been described in a limited number of case reports, yet none, to our knowledge, with rapid bilateral destruction requiring two-staged conversion to total hip replacement., (© 2022 The Authors.)

Background: Tibial component aseptic loosening remains problematic in primary total knee arthroplasty (TKA). Influential factors include component design, metallurgy, and cement technique. Additionally, reports advocate for longer tibial stem fixation in high body mass index (BMI) patients. We have utilized a single stem length modular titanium baseplate in patients regardless of BMI, bone quality, or malalignment. We report the survivorship of this implant with focus on the impact of elevated BMI and postoperative malalignment., Methods: We retrospectively reviewed patients who underwent TKA with a single modular titanium baseplate with a cruciate-shaped keel between 2004 and 2018. In total, 2,949 TKAs with a minimum of 1-year follow-up were included. The mean follow-up was 7 years. The primary outcome was component failure stratified by BMI and postoperative malalignment. High viscosity cement was utilized in all cases. Chi-squared and t-tests were used to compare outcome variables across groups., Results: Eighty-five implants (2.8%) were revised with 46 (1.6%) for aseptic loosening. Failure was not associated with BMI, gender, American Society of Anesthesiologists class, or Charlson Comorbidity Index. There was no difference in failure rate by BMI (P = .26) or by malalignment (outside of 3° from neutral mechanical axis) (P = .67). Age was associated with failure as patients with failed TKAs were younger (61 vs 65, P < .01)., Conclusion: This design of a specific modular titanium base plate with a cruciate-shaped keel and grit blast surface demonstrated 99% survivorship regardless of patient BMI or malalignment over 7-year follow-up period. Consistent cement technique with high viscosity cement indicates that component design remains an important variable impacting survivorship in TKA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Advances in polyethylene bearing characteristics have led to various options for total knee arthroplasty. We examine trends in use of polyethylene in the United States., Methods: An analysis of American Joint Replacement Registry data from 2012 to 2019 for primary total knee arthroplasty procedures was conducted. Design and manufacturing characteristics were obtained and validated in the American Joint Replacement Registry dataset. Polyethylene bearing design and manufacturing use characteristics were compared by year, gender, age group, and geographic region of the procedure. Descriptive analysis was performed., Results: We identified 993,292 cases over the study period. In total, 791,233 (80%) cases had complete device data available and were included in analysis. In addition, 366,280 (49.4%) cases utilized minimally stabilized bearings compared to 374,809 (50.6%) for posterior-stabilized bearings. Posterior-stabilized use was stable over the study period and highest in the Northeast (64.5%; P < .0001). Cruciate-retaining use decreased from 29.7% to 20.2% and anterior-stabilized use increased from 17.4% to 25.2%. Conventional polyethylene use decreased from 42.8% to 21.9%, and was highest in the 81+ age group (37.8%; P < .0001) and Northeast (43.0%; P < .0001). Highly cross-linked polyethylene (HXLPE) with antioxidant use increased from 9.08% to 31.8%, while HXLPE without antioxidant use remained constant., Conclusion: There was an increase in use of anterior-stabilized and pivot bearings and an increase in use of HXLPE with antioxidant. Additionally, there were noted age group and regional differences in the use of various bearings. Further study should evaluate if these changing utilization trends are related to clinical outcomes, or due to regional training, preferences, or manufacturer pressures., Level of Evidence: Level III, retrospective., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Currently, there are little data on performance, safety, or return to downhill skiing after total joint arthroplasty (TJA). This leaves surgeons with little information for patient counseling regarding skiing., Methods: An online survey was sent to 4360 patients who had undergone at least 1 primary TJA at a single academic center over the past 10 years (4 surgeons). The survey asked patients about their prior and current skiing activity including ability level, limitations, and reoperations. Demographics, patient-reported outcomes, and reoperations were also captured through chart review. Chi-squared, analysis of variance, and t-tests were used to compare demographics and outcomes. Paired t-tests were used to compare preoperative and postoperative skiing levels., Results: Of the 763 survey respondents, the average follow-up was 4.4 years (range 0.5-10.3). In total, 35.6% had never skied, 26.5% had not skied in the 5 years prior to surgery (remote), and 37.9% had skied in the 5 years prior to surgery (recent). Seventy percent of recent skiers returned to skiing after surgery, compared to 11.9% of remote skiers. The majority of skiers, mostly advanced, returned to their prior level. There was no difference in return rates in those with a single total hip arthroplasty vs total knee arthroplasty vs multiple TJAs. Rates of reoperation were not significantly different between patients who did and did not return to skiing., Conclusion: The majority of recent skiers were able to return to skiing after TJA at their same level without an increase in reoperation rate. Further studies are needed to determine long-term consequences of skiing after TJA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To understand whether the Comprehensive Care for Joint Replacement (CJR) program induces participating hospitals to (1) preferentially select lower risk patients, (2) reduce 90-day episode-of-care costs, (3) improve quality of care, and (4) achieve greater cost reduction during its second year, when downside financial risk was applied., Data Sources: We identified beneficiaries of age 65 years or older undergoing hip or knee joint replacement in the 100% sample of Medicare fee-for-service inpatient (Part A) claims from January 1, 2013 to August 31, 2017. Cases were linked to subsequent outpatient, Part B, home health agency, and skilled nursing facility claims, as well as publicly available participation status for CJR., Study Design: We estimated the effect of CJR for hospitals in the 67 metropolitan statistical areas (MSA) selected to participate in CJR (785 hospitals), compared to those in 104 non-CJR MSAs (962 hospitals; maintaining fee-for-service). A difference-in-differences approach was used to detect patient selection, as well as to compare 90-day episode-of-care costs and quality of care between CJR and non-CJR hospitals over the first two performance years., Data Collection: We excluded 172 hospitals from our analysis due to their preexisting BPCI participation. We focused on elective admissions in the main analysis., Principal Findings: While reductions in 90-day episode-of-care costs were greater among CJR hospitals (-$902, 95% CI: -$1305, -$499), largely driven by a 16.8% (p < 0.01) decline in 90-day spending in skilled nursing facilities, CJR hospitals significantly reduced the 90-day readmission rate (-3.9%; p < 0.05) and preferentially avoided patients aged 85 years or older (-5.9%; p < 0.01) and Black (-7.0%; p < 0.01). Cost reduction was greater in 2017 than in 2016, corresponding to the start of downside risk., Conclusions: Participation in CJR was associated with a modest cost reduction and a reduction in 90-day readmission rates; however, we also observed evidence of preferential avoidance of older patients perceived as being higher risk among CJR hospitals., (© 2021 Health Research and Educational Trust.)

Genicular nerve radiofrequency ablation (RFA) is increasingly being performed to treat chronic pain due to knee osteoarthritis (KOA). This narrative review provides a concise summary of the relevant neuroanatomy, randomized controlled trials, appropriate patient selection, and safety relating to genicular RFA. Cadaveric studies demonstrate significant variability in the location of the genicular nerves, which has stimulated debate about the ideal target locations for genicular RFA. Despite this, favorable outcomes have been observed in studies targeting only the superior medial genicular nerve, inferior medial genicular nerve, and superior lateral genicular nerve. Several randomized controlled trials demonstrate superiority of genicular RFA compared with intra-articular steroid, viscosupplementation, and oral analgesics. Genicular RFA of the superior medial genicular nerve, inferior medial genicular nerve, and superior lateral genicular nerve appears to be an effective treatment for painful KOA, but targeting additional sensory nerves may further improve treatment success. Although genicular RFA appears relatively safe on the basis of the available data, additional large-scale studies are needed to provide greater confidence., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Academy of Pain Medicine.All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The spinopelvic relationship in regard to total hip arthroplasty has become a topic of increasing interest in recent years. Hip arthritis and a stiff lumbar spine create a situation where the spinopelvic junction has decreased mobility, which in turn increases the risk of instability after total hip arthroplasty as the femoral acetabular joint must undergo increased motion. Regardless of the approach, surgeons should be aware of the risk of instability in patients with a stiff spinopelvic junction and the necessary modifications to component positioning to avoid postoperative instability. As many direct anterior approach surgeons use fluoroscopy for intraoperative navigation, anterior approach surgeons must also understand how to best use this technology to improve component positioning., Methods: In this article, we address the basic concepts surrounding spinopelvic stiffness, the intraoperative component adjustments necessary for optimizing stability, and how to appropriately use fluoroscopy for navigation in the direct anterior approach., Conclusions: Appropriate use of intraoperative fluoroscopy includes understanding the impact of parallax and distortion, properly recreating the patient's standing functional pelvic plane intraoperatively and adjusting the cup's target position based on a preoperative understanding of the patient's spinopelvic motion., (Published by Elsevier Inc.)

Introduction: We evaluated the use of text messages to communicate information to patients whose surgeries were postponed because of the COVID-19 restriction on elective surgeries. Our hypothesis was that text messaging would be an effective way to convey updates., Methods: In this observational study, 295 patients received text messaging alerts. Eligibility included patients who had their surgery postponed and had a cell phone that received text messages. Engagement rates were determined using embedded smart links. Patient survey responses were collected., Results: A total of 3,032 texts were delivered. Engagement rates averaged 90%. Survey responses (n = 111) demonstrated that 98.2% of patients liked the text messages and 95.5% said that they felt more connected to their care team; 91.9% of patients agreed that the text updates helped them avoid calling the office. Patients with higher pain levels reported more frustration with their surgery delay (5.3 versus 2.8 on 1 to 10 scale, P value < 0.01). More frustrated patients wished they received more text messages (24.4% versus 4.6%, P value = 0.04) and found the content less helpful (8.2 versus 9.2 on 1 to 10 scale, P value = 0.01)., Conclusion: Text messaging updates are an efficient way to communicate with patients during the COVID-19 pandemic., (Copyright © 2021 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Orthopaedic Surgeons.)

Background: This study aimed to evaluate clinical and biomechanical changes in self-report survey, quadriceps strength and gait analysis over 3- and 6-months post-total knee arthroplasty (TKA) and confirm the immediate effects of two forms of kinetic biofeedback on improving inter-limb biomechanics during a physically demanding decline walking task., Methods: Thirty patients with unilateral TKA underwent testing at 3- and 6-months following surgery. All underwent self-report survey, quadriceps strength and gait analysis testing. Patients were assigned to one of two types of biofeedback [vertical ground reaction force (vGRF), knee extensor moment (KEM)]., Results: No decrease in gait asymmetry was observed in non-biofeedback trials over time (p > 0.05), despite significant improvements in self-report physical function (p < 0.01, Cohen d = 0.44), pain interference (p = 0.01, Cohen d = 0.68), numeric knee pain (p = 0.01, Cohen d = 0.74) and quadriceps strength (p = 0.01, Cohen d = 0.49) outcomes. KEM biofeedback induced significant decrease in total support moment (p = 0.05, Cohen f 2  = 0.14) and knee extensor moment (p = 0.05, Cohen f 2  = 0.21) asymmetry compared to using vGRF biofeedback at 6-months. vGRF biofeedback demonstrated significant decrease in hip flexion kinematic asymmetry compared to KEM biofeedback (p = 0.05, Cohen f 2  = 0.18) at 6-months., Conclusion: Gait compensation remained similar from 3- to 6-months during a task requiring greater knee demand compared to overground walking post-TKA, despite improvements in self-report survey and quadriceps strength. Single session gait symmetry training at 6-month supports findings at 3-month testing that motor learning is possible. KEM biofeedback is more effective at immediately improving joint kinetic loading compared to vGRF biofeedback post-TKA., (Published by Elsevier B.V.)

Background: Two-stage revision remains the standard of care for prosthetic joint infection after total hip arthroplasty. However, there are substantial complications associated with articulating antibiotic hip spacers. Handmade and molded spacers have been shown to have higher rates of spacer fracture than antibiotic-coated prostheses (ACPs). The aim of this study is to review outcomes with an implant that is often categorized as an ACP spacer, the Zimmer-Biomet StageOne Select Femoral Spacer (ZBSO)., Methods: A retrospective review was performed of 63 patients who underwent placement of a ZBSO. Patients were compared based on whether or not an extended trochanteric osteotomy (ETO) was performed using Fisher's exact and t-tests., Results: Five patients were excluded due to lack of follow-up or death shortly after stage 1 surgery, leaving 58 patients. Spacer fracture was noted in 5 of 58 patients (8.6%). Sixteen patients underwent ETO and 25.0% suffered a spacer fracture compared to 2.3% without ETO (odds ratio 13.7, P = .0248). There was no association between patient demographics or ETO length and spacer fracture. Two patients had periprosthetic fractures (3.4%) and 4 had dislocations (6.9%). Forty-nine patients (84.4%) went on to second-stage revision; of those 26.5% failed to clear the infection and required an average of 2.2 additional surgeries., Conclusion: The ZBSO spacer has overall complication rates similar to previously reported spacer series. Although the ZBSO looks like an ACP spacer, in the setting of ETO, it behaves like a molded or handmade spacer with a high rate of spacer fracture (25%) due to the small diameter of the core. This implant should be used with caution in combination with an ETO., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Aims: Porous metaphyseal cones can be used for fixation in revision total knee arthroplasty (rTKA) and complex TKAs. This metaphyseal fixation has led to some surgeons using shorter cemented stems instead of diaphyseal engaging cementless stems with a potential benefit of ease of obtaining proper alignment without being beholden to the diaphysis. The purpose of this study was to evaluate short term clinical and radiographic outcomes of a series of TKA cases performed using 3D-printed metaphyseal cones., Methods: A retrospective review of 86 rTKAs and nine complex primary TKAs, with an average age of 63.2 years (SD 8.2) and BMI of 34.0 kg/m 2 (SD 8.7), in which metaphyseal cones were used for both femoral and tibial fixation were compared for their knee alignment based on the type of stem used. Overall, 22 knees had cementless stems on both sides, 52 had cemented stems on both sides, and 15 had mixed stems. Postoperative long-standing radiographs were evaluated for coronal and sagittal plane alignment. Adjusted logistic regression models were run to assess malalignment hip-knee-ankle (HKA) alignment beyond ± 3° and sagittal alignment of the tibial and femoral components ± 3° by stem type., Results: No patients had a revision of a cone due to aseptic loosening; however, two had revision surgery due to infection. In all, 26 (27%) patients had HKA malalignment; nine (9.5%) patients had sagittal plane malalignment, five (5.6%) of the tibia, and four (10.8%) of the femur. After adjusting for age, sex, and BMI, there was a significantly increased risk for malalignment when a cone was used and both the femur and tibia had cementless compared to cemented stems (odds ratio 3.19, 95% confidence interval 1.01 to 10.05)., Conclusion: Porous 3D-printed cones provide excellent metaphyseal fixation. However, these central cones make the use of offset couplers difficult and may generate malalignment with cementless stems. We found 3.19-times higher odds of malalignment in our TKAs performed with metaphyseal cones and both femoral and tibial cementless stems. Cite this article: Bone Joint J  2021;103-B(6 Supple A):150-157.

In complex primary and revision total knee arthroplasty (TKA), rotating-hinge TKA (RH-TKA) prostheses play an important role. Compared to early fixed-hinge knee designs, new implants that include rotating platforms and improved hinge constructs may offer improvements in both survival and clinical outcomes. We sought to evaluate early survival following complex primary and revision TKA with a rotating-hinge knee prosthesis. We retrospectively reviewed a consecutive series of patients (n=47, 48 knees) who underwent revision TKA using an RH-TKA system. The mean age was 73 years (range, 37 - 86). The mean body mass index was 29 (range, 16.3 - 45.9) and the median ASA score was 3 (IQR, 2 - 3). As mortality was high, we performed a Kaplan-Meier analysis to evaluate survival, with death as failure. The median follow-up was 2.5 years (range, 0.07 - 9.8). Revision-free survival was 97% at a median 2.5 years of follow-up. Overall mortality was 46% (17/37) and survival free from death was 69% (49% - 82%) at a median of 2.5 years. Most reoperations were due to infection (5/12), following by wound-related complications (2/12) and hematomas (2/12). A high postoperative complication rate and mortality are evident in TKA using a hinged knee prosthesis in complex revision TKA. If the indication and surgical technique are matched to the complexity of the case, this type of implant offers a feasible salvage procedure.

Background: Distortion is an intrinsic phenomenon associated with image-intensified fluoroscopy that is both poorly understood and infrequently appreciated by orthopedic surgeons. Little information exists regarding its potential influence on intraoperative parameters during orthopedic surgery, let alone during direct anterior (DA) total hip arthroplasty (THA). The purpose of this study was to quantify the amount of potential error caused by fluoroscopic distortion during DA THA., Methods: Intra-operative fluoroscopic pelvic images from 74 DA THAs were reviewed by two independent readers. All images were obtained using the same fluoroscopic C-arm unit with a radiopaque grid attached to the image intensifier. The vertical distortion from a straight central horizontal line at the peripheries of images were measured and summed to yield the combined vertical distortion similar to how a surgeon calculates a side to side comparison of limb lengths. Simple linear regression was used to evaluate associations between total distortion and patient demographics, operating theaters, and various operative parameters., Results: The average combined distortion was 10.0mm (range 2.0-20.0mm). There was a significant difference in the average distortion observed in different theaters (P < .001). There was no association between distortion and patient demographics or fluoroscopic time (all, P > .05)., Conclusion: Fluoroscopic distortion is unpredictable and can cause a substantial amount of error when comparing limb lengths during DA THA. This is a critical finding as this amount of inaccuracy could lead to unintended implant positioning and limb-length discrepancies if unaccounted for., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Total nucleated cell (TNC) count and differential are used to classify joint effusions as inflammatory or noninflammatory. Further diagnostic evaluation and management is contingent on this classification. TNC count can be measured by automated analyzers or by manual assessment using a hemocytometer. Studies have raised concerns regarding the accuracy of TNC counts measured by automated instruments, particularly in the setting of joint arthroplasty. The objective of this study was to determine whether metallosis, a complication of total hip arthroplasty in which metal debris accumulates in periprosthetic tissues and synovial fluid, is associated with inaccurate TNC counts in synovial fluid., Methods: We compared the accuracy of cell counts measured by the Sysmex XN-1000 and Beckman Coulter Iris iQ200 with the gold standard of manual assessment using a hemocytometer in synovial fluid from patients with suspected metallosis and in fluid obtained from controls from patients with native joints and a history of arthroplasty for other indications., Results: TNC counts produced by automated analyzers were associated with increased levels of discordance (relative to manual counts) in patients with metallosis. Metallosis was not associated with increased levels of discordance for RBC counts or WBC differentials. The Sysmex XN flagged all but 1 metallosis sample for manual verification of the results., Conclusions: Automated methods are generally reliable for analysis of synovial fluid. TNC counts can be inaccurate in the context of metallosis following total hip arthroplasty. Laboratories should correlate automated cell counts with a microscopic assessment of the specimen, as recommended by instrument manufacturers., (© American Association for Clinical Chemistry 2020. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Although spinopelvic stiffness is known to contribute to instability following total hip arthroplasty (THA), it is unknown whether use of an anterior surgical approach is associated with decreased postoperative instability rates in patients with lumbar spondylosis or fusion., Methods: A retrospective review was performed of 1750 patients who underwent primary THA at our institution over an 8-year time period. Radiographic and chart review was performed evaluating for dislocations. Lumbar and pelvic radiographs were used to identify the presence of spondylosis and/or instrumented fusion. Patients were then divided into non-spondylosis and spondylosis or fusion groups to compare dislocation rates by surgical approach., Results: In total, 54.4% of THA patients had an anterior approach (n = 952) and 54.6% had lumbar spondylosis or instrumented fusion (n = 956). There were 29 dislocations in total (1.7%), with less occurring in anterior approach patients (0.6% vs 2.9%, P < .001). In the patients without lumbar spondylosis, there were less dislocations in the anterior approach group (0.2% vs 1.7%, P = .048). Likewise, in patients with lumbar spondylosis or fusion, there were less dislocations in the anterior approach group (1.0% vs 3.8%, P = .004). Using logistic regression, there was a 4.1× increased risk of dislocation with a posterior approach vs an anterior approach in the spondylosis or fusion group (P = .011)., Conclusion: Patients with lumbar spondylosis or fusion have high rates of instability. At our institution, we found that utilization of an anterior surgical approach substantially mitigated this risk., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The goal was to determine if the addition of a metaphyseal stem extension limits micromotion of a cementless tibial component during cyclic loading in primary total knee arthroplasty. The hypothesis tested was that the use of a 50-mm stem extension on a cementless tibial component would limit motion compared with an identical cementless component without a stem extension., Methods: The study used 3 variations of a tibial component from the same total knee arthroplasty system. Group 1 consisted of a cementless tibial component without a stem extension. Group 2 used the same cementless component as group 1, but with the addition of a short 50-mm stem. Group 3 consisted of a cemented tibial component without a stem extension to serve as a "control" (gold standard). The tibial specimens were implanted into a synthetic bone model and tested using a physiological medial-lateral 60/40 load distribution for 5000 cycles., Results: The results demonstrated a significant decrease in motion at the anterior region of the cementless stem extension (group 2) components compared with the cementless with no stem extension (group 1). The cementless with stem extension (group 2) demonstrated similar results at all cycles to the cemented (group 3) components at the anterior region., Conclusion: The addition of a short metaphyseal stem (50mm) to a keel plus 4-peg tibial component design provides a significant reduction in micromotion during cyclic loading of a cementless tibial baseplate in a synthetic foam bone model, similar to a cemented implant., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty, carrying significant economic and personal burden. The goal of this study is to use an established database to analyze socioeconomic variables and assess their relationship to PJI. Additionally, we sought to evaluate whether socioeconomic factors, along with other known risk factors of PJI, when controlled for in a statistical model affected the familial risk of PJI., Methods: With approval from our Institutional Review Board we performed a population-based retrospective cohort study on all primary total joint arthroplasty cases of the hip or knee (n = 85,332), within a statewide database, between January 1996 and December 2013. We excluded 9854 patients due to age <18 years, missing data, history of PJI prior to index procedure, and no evidence of 2-year follow-up (excluding those with PJI). Cases that developed PJI following the index procedure (n = 2282) were compared to those that did not (n = 73,196)., Results: After adjusting for covariates, patients with Medicaid as a primary payer were at greater risk for experiencing PJI (relative risk 1.40, 95% confidence interval [CI] 1.08-1.82, P = .01). There was no difference in risk between the groups associated with education level or median household income (all, P > .05). First-degree relatives of patients who develop PJI (hazard ratio 1.66, 95% CI 1.23-2.24, P = .001) and first-degree and second-degree relatives combined (hazard ratio 1.39, 95% CI 1.09-1.77, P = .007) were at greater risk despite controlling for the above socioeconomic factors., Conclusion: Our study provides further support that genetic factors may underlie PJI as we did observe significant familial risk even after accounting for socioeconomic factors and payer status. We did not find a correlation between education level or household income and PJI; however, Medicaid payees were at increased risk. Continued study is needed to define a possible heritable disposition to PJI in an effort to optimize treatment and possibly prevent this complication., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The COVID-19 pandemic has created widespread changes across all of health care. As a result, the impacts on the delivery of orthopedic services have been challenged. To ensure and provide adequate health care resources in terms of hospital capacity and personnel and personal protective equipment, service lines such as adult reconstruction and lower limb arthroplasty have stopped or substantially limited elective surgeries and have been forced to re-engineer care processes for a high volume of patients. Herein, we summarize the similar approaches by two arthroplasty divisions in high-volume academic referral centers in (1) the cessation of elective surgeries, (2) workforce restructuring, (3) phased delivery of outpatient and inpatient care, and (4) educational restructuring., (Copyright © 2020 Elsevier Inc. All rights reserved.)