Search

Previous studies have sought to determine the effects of total knee arthroplasty (TKA) using kinematic alignment (KA) versus mechanical alignment (MA) to reproduce the native knee alignment and soft tissue envelope for improved patient satisfaction. There are limited studies that compare acute perioperative outcomes between KA and MA patients as it pertains to pain-related opioid consumption and hospital length of stay (LOS). This study aims to compare early KA and MA in restoring function and rehabilitation after surgery to reduce hospitalization and opioid consumption.A retrospective review of 42 KA and 58 MA primary TKA patients performed by a single surgeon between 2020-2021 was conducted. Demographics were controlled between groups and radiographic measurements and functional outcomes were compared. Pain was evaluated with inpatient/outpatient morphine milligram equivalents (MME) and visual analogue scale (VAS) scores. Mobility was assessed using multiple measures by a physical therapist. Mean preoperative and 3-month postoperative flexion range of motion (ROM) were analyzed, and overall complications, LOS, and non-home discharge between groups compared. Continuous variables were compared using the Wilcoxon rank-sum test, and categorical variables were compared using the chi-square or Fisher exact test. Statistical significance was set at P 0.05.KA patients had shorter LOS (1.8 vs 3.1 days) and less cumulative opioid requirements compared to MA patients (578 vs 1253 MME). On postoperative day 0, KA patients ambulated on average twice the distance of MA patients (20 vs 6.5 feet). KA patients had residual tibia component in varus (1.4° vs -0.3°), femoral component in valgus (-1.9° vs 0.2°), and valgus joint line obliquity compared with MA (-1.5° vs 0.2°). There were no significant differences between 3-month postoperative flexion arc motion, discharge destination, KOOS or SF-12 outcomes, and surgical complication rates between groups.By restoring the native joint line obliquity and minimizing the frequency of ligament releases, KA for TKA may improve pain relief, early mobility, and decreased length of stay compared with traditional methods of establishing neutral limb axis by MA.

Inflammation and tissue fibrosis co-exist and are causally linked to organ dysfunction. However, the molecular mechanisms driving immune-fibroblast crosstalk in human cardiac disease remains unexplored and there are currently no therapeutics to target fibrosis. Here, we performed multi-omic single-cell gene expression, epitope mapping, and chromatin accessibility profiling in 38 donors, acutely infarcted, and chronically failing human hearts. We identified a disease-associated fibroblast trajectory marked by cell surface expression of fibroblast activator protein (FAP), which diverged into distinct myofibroblasts and pro-fibrotic fibroblast populations, the latter resembling matrifibrocytes. Pro-fibrotic fibroblasts were transcriptionally similar to cancer associated fibroblasts and expressed high levels of collagens and periostin (POSTN), thymocyte differentiation antigen 1 (THY-1), and endothelin receptor A (EDNRA) predicted to be driven by a RUNX1 gene regulatory network. We assessed the applicability of experimental systems to model tissue fibrosis and demonstrated that 3 different in vivo mouse models of cardiac injury were superior compared to cultured human heart and dermal fibroblasts in recapitulating the human disease phenotype. Ligand-receptor analysis and spatial transcriptomics predicted that interactions between C-C chemokine receptor type 2 (CCR2) macrophages and fibroblasts mediated by interleukin 1 beta (IL-1β) signaling drove the emergence of pro-fibrotic fibroblasts within spatially defined niches. This concept was validated through in silico transcription factor perturbation and in vivo inhibition of IL-1β signaling in fibroblasts where we observed reduced pro-fibrotic fibroblasts, preferential differentiation of fibroblasts towards myofibroblasts, and reduced cardiac fibrosis. Herein, we show a subset of macrophages signal to fibroblasts via IL-1β and rewire their gene regulatory network and differentiation trajectory towards a pro-fibrotic fibroblast phenotype. These findings highlight the broader therapeutic potential of targeting inflammation to treat tissue fibrosis and restore organ function.

INTRODUCTION This study compared costs, length of visit, and utilization trends for patients with fractures seen in an immediate care orthopaedic center (I-Care) versus the emergency department (ED) in a major metropolitan area. METHODS A retrospective chart review of consecutive patients seen on an outpatient basis in the ED and I-Care over a 6-month period was conducted. Patient demographics, procedures done, care category, estimated costs, and disposition information were included for statistical analysis. Within the low-acuity fracture care group, a cost-comparison analysis was conducted. RESULTS A total of 610 patients met inclusion criteria with 311 seen in I-Care and 299 in the ER. I-Care patients were more likely to have low-acuity injuries compared with ED patients (60.1% versus 18.1%, P < 0.001). The length of visit was longer for patients seen in the ED compared with I-Care (6.1 versus 1.43 hours, P value < 0.001). A cost analysis of low-acuity patients revealed that an estimated $62,150 USD could have been saved in healthcare costs by the initial diversion of low-acuity patients seen in the ER to I-Care during the study period. DISCUSSION These results suggest that the I-Care orthopaedic urgent care model is a more cost-effective and more efficient alternative to the ED for patients with fractures requiring procedural treatment and low-acuity patients managed on an outpatient basis.

Background: Owing to the COVID-19 pandemic, there has been a large shift in health care toward virtual platforms. This study analyzed patient and physician satisfaction with telehealth during the height of the pandemic within the division of sports medicine. Methods: All sports medicine patients who completed a telemedicine visit from March 30, 2020, through April 30, 2020, were sent a 14-question Likert scale (1-5/5) survey. Sports medicine physicians who used telemedicine were sent a separate 14-question Likert scale (1-5/5) survey at the end of the study period. Factors influencing patient satisfaction were determined using a multivariate linear regression model. Results: A total of 143 patients and 9 sports medicine attendings completed the surveys. Most patients were "satisfied" (4/5) or "very satisfied" (5/5) (88.8%). A multivariate linear regression determined that patients who believed they had a greater ability to adopt new technology and were more effective at communicating questions/concerns to their physicians had greater satisfaction (p = 0.009 and p = 0.015, respectively). Most physicians were either "satisfied" (4/5) or "very satisfied" (5/5) (75.0%). On average, physicians felt that physical examinations conducted through telemedicine were "moderately effective" (2.75/5.00 ± 1.3), that they were "fairly confident" (3.86/5.00 ± 0.83) in their diagnoses, and that most sports medicine attendings plan to use telemedicine in the future (87.5%). Conclusion: Telehealth emerged as a valuable tool for the delivery of health care to sports medicine patients during the COVID-19 pandemic. Patients and physicians reported high levels of satisfactions with its use, and this study further identifies areas that can improve the patient and physician experience.

Cardiac fibrosis is causally linked to heart failure pathogenesis and adverse clinical outcomes. However, the precise fibroblast populations that drive fibrosis in the human heart and the mechanisms that govern their emergence remain incompletely defined. Here, we performed Cellular Indexing of Transcriptomes and Epitomes by sequencing (CITE-seq) in 22 explanted human hearts from healthy donors, acute myocardial infarction (MI), and chronic ischemic and non-ischemic cardiomyopathy patients. We identified a fibroblast trajectory marked by fibroblast activator protein (FAP) and periostin (POSTN) expression that was independent of myofibroblasts, peaked early after MI, remained elevated in chronic heart failure, and displayed a transcriptional signature consistent with fibrotic activity. We assessed the applicability of cardiac fibrosis models and demonstrated that mouse MI, angiotensin II/phenylephrine infusion, and pressure overload models were superior compared to cultured human heart and dermal fibroblasts in recapitulating cardiac fibroblast diversity including pathogenic cell states. Ligand-receptor analysis and spatial transcriptomics predicted interactions between macrophages, T cells, and fibroblasts within spatially defined niches. CCR2+monocyte and macrophage states were the dominant source of ligands targeting fibroblasts. Inhibition of IL-1β signaling to cardiac fibroblasts was sufficient to suppress fibrosis, emergence, and maturation of FAP+POSTN+fibroblasts. Herein, we identify a human fibroblast trajectory marked by FAP and POSTN expression that is associated with cardiac fibrosis and identify macrophage-fibroblast crosstalk mediated by IL-1β signaling as a key regulator of pathologic fibroblast differentiation and fibrosis.

Introduction Although a substantial portion of the United States population has been infected with and recovered from Coronavirus Disease-19 (COVID-19), many patients may have persistent symptoms and complications from disease-driven respiratory disease, arrhythmias, and venous thromboembolism (VTE). With institutions resuming elective total joint arthroplasties (TJA), it is unclear whether a prior resolved diagnosis of COVID has any implications on postoperative outcomes. Methods All elective TJA performed in 2021 at our institution were retrospectively reviewed and a history of prior COVID+ result recorded. Baseline demographics, days from prior COVID+ result to surgery date, preoperative methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, and laboratory markers were obtained to determine baseline characteristics. Postoperative estimated blood loss (EBL), length of stay (LOS), rate of revision surgery, and discharge destination were compared between groups. Perioperative and postoperative rates of VTE, urinary tract infection (UTI), pneumonia, postoperative oxygen supplementation, cardiac arrhythmia, renal disease, sepsis, and periprosthetic joint infections within six months of surgery were recorded. Results Of the 155 elective TJA performed in 2021, 24 patients had a prior COVID+ diagnosis with a mean of 253 days from positive result to surgery date. There were no significant differences in baseline demographics, comorbidities, and preoperative lab markers between groups. Surgeries on patients with a prior COVID+ had a significantly higher EBL (260 vs 175cc), but postoperative outcomes of VTE, UTI, pneumonia, oxygen supplementation requirement, nares MRSA+, cardiac disease, and infection rates between groups were similar. Bivariate logistic regression revealed increased days from COVID+ diagnosis (6 months) to surgery date were associated with a shorter LOS. Conclusion Although a prior COVID+ diagnosis had increased intraoperative blood loss, there were no significant differences in respiratory, infectious, cardiac, and thromboembolic complications up to six months after elective TJA. This study suggests that asymptomatic C+ patients receiving elective TJA do not require more aggressive prophylactic anticoagulation or antibiotic regimens to prevent VTE or perioperative infections. As institutions around the nation resume pre-COVID rates of arthroplasty surgeries, a prior diagnosis of COVID appears to have no effects on postoperative complications.

Background As healthcare economics shifts towards outcomes-based bundled payment models, providers must understand the evolving dynamics of medical optimization and fluid resuscitation prior to elective surgery. Dehydration is an overlooked modifiable risk factor that should be optimized prior to elective total knee arthroplasty (TKA) to reduce postoperative complications and inpatient costs. Methods All primary TKA from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database, and patients were compared based on dehydration status: Blood Urea Nitrogen Creatinine ratio (BUN/Cr) 65 years and normalized gender-adjusted Cr values was also performed. Results The analysis included 344,744 patients who underwent TKA. Adjusted multivariate logistic regression analysis showed that the severely dehydrated cohort had a greater risk of non-home discharge, postoperative transfusion, postoperative deep vein thrombosis (DVT), and increased length of stay (LOS) (all p p Conclusion BUN/Cr > 20 is an important preoperative diagnostic tool to identify at-risk dehydrated patients. Providers should optimize dehydration to prevent complications, decrease costs, and improve discharge planning. Level of evidence Level III; Retrospective Case-Control Design; Prognosis Study.

Pycnodysostosis (PYCD) is an autosomal recessive lysosomal storage disorder of the bone which leads to stereotypical abnormalities consisting of, but not limited to, sclerotic and fragile bone, shortened distal phalanges, and obtuse mandibular angle. Current literature describes the otolaryngological manifestations and treatment of this disorder; however, the treatment of orthopedic fractures in PYCD patients is seldom described and remains a controversial topic. We aim to systematically review the current evidence regarding the optimal treatment of PYCD patients with fractures. We performed a literature search using PubMed, MEDLINE, Web of Science, and Google Scholar databases. Elig-ibility criteria consisted of English-language literature of PYCD patients undergoing treatment for orthopedic surgery fractures. Non-English papers or literature focused on maxillofacial manifestations/treatment were excluded. The database search resulted in the identification of 500 articles. After removing duplicates and enforcing our inclusion criteria, 29 case reports/series (40 patients) were included. The average age was 31.25 (-±18.2) years, with 57.5% of patients being female. Overall, 62.5% of patients had consanguineous parents. Additionally, 86.2% reported a history of previous fractures while 47.5% reported a spontaneous or minor trauma fracture, with most fractures occurring in the femur (60.0%) and tibia (40.0%). Radiographic features consisted of densification in the femur 45.0% (18/40), tibia 37.5% (15/40), and spine 25.0% (10/40). Overall, 84.2% of patients were treated with surgical management consisting of internal plate fixation (IPF) (48.3%), intramedullary fixation (20.7%), and Ilizarov external fixation (IEF) (13.8%). Overall, the refracture rate was 25.0% and was lowest in intramedullary fixation (0/6), compared to IPF (3/14) and IEF (3/4). Average time until refracture was 40.6 months (3-132 months). Long-term follow-up is recommended in patients with PYCD due to the propensity for fractures/refractures. While this study provides the groundwork for the treatment of PYCD patients, further research with higher-evidence studies should be conducted to establish the optimal orthopedic treatment of this disorder.

Per capita fructose consumption has increased 100-fold over the last century1. Epidemiological studies suggest that excessive fructose consumption, and especially consumption of sweet drinks, is associated with hyperlipidaemia, non-alcoholic fatty liver disease, obesity and diabetes2–7. Fructose metabolism begins with its phosphorylation by the enzyme ketohexokinase (KHK), which exists in two alternatively spliced forms8. The more active isozyme, KHK-C, is expressed most strongly in the liver, but also substantially in the small intestine9,10 where it drives dietary fructose absorption and conversion into other metabolites before fructose reaches the liver11–13. It is unclear whether intestinal fructose metabolism prevents or contributes to fructose-induced lipogenesis and liver pathology. Here we show that intestinal fructose catabolism mitigates fructose-induced hepatic lipogenesis. In mice, intestine-specific KHK-C deletion increases dietary fructose transit to the liver and gut microbiota and sensitizes mice to fructose’s hyperlipidaemic effects and hepatic steatosis. In contrast, intestine-specific KHK-C overexpression promotes intestinal fructose clearance and decreases fructose-induced lipogenesis. Thus, intestinal fructose clearance capacity controls the rate at which fructose can be safely ingested. Consistent with this, we show that the same amount of fructose is more strongly lipogenic when drunk than eaten, or when administered as a single gavage, as opposed to multiple doses spread over 45 min. Collectively, these data demonstrate that fructose induces lipogenesis when its dietary intake rate exceeds the intestinal clearance capacity. In the modern context of ready food availability, the resulting fructose spillover drives metabolic syndrome. Slower fructose intake, tailored to intestinal capacity, can mitigate these consequences. Modulating the capacity of the intestinal epithelium to catabolize fructose is shown to alter fructose-induced lipogenesis in the mouse liver, suggesting that fructose clearance in the small intestine protects from steatosis.

Background: A major consequence of the COVID-19 pandemic on the U.S. healthcare system has been the rapid transition away from in-person healthcare visits to telehealth. This study analyzed patient and surgeon satisfaction in the utilization of telehealth within the hand surgery division during the COVID-19 pandemic. Methods: All hand surgery patients who completed a telemedicine visit from March 30th, 2020 through April 30th, 2020 completed a 14-question survey via e-mail. Hand surgeons who participated in telemedicine completed a separate 14-question survey. Survey results were presented descriptively (mean ± standard deviation) and patient factors influencing satisfaction were determined using univariate and multivariate proportional modeling. Results: 89 patients and five surgeons completed the surveys. Patients were very satisfied with their telemedicine visits (4.21/5.00 ± 0.89). Multivariate proportional modeling determined patients who found it “very easy” (5/5) to arrange telemedicine visits had greater satisfaction (OR = 4.928; 95% CI = 0.94 to 25.84) compared to those who found it “difficult” (2/5) (p = 0.059). Patients who believed they could ask/relay questions/concerns “extremely effectively” (5/5) had greater satisfaction (OR = 55.236; CI = 11.39 to 267.80) compared to those who asked/relayed questions only “slightly effective” to “moderately effectively” (p < 0.001). Surgeons were similarly satisfied with their telemedicine experience (4.00/5.00 ± 0.89) and were confident in their diagnoses (4.20/5.00 ± 0.84). All surgeons responded they will continue using telemedicine. 30.7% of patients would choose telemedicine over an inperson visit. Conclusions: Telemedicine provides a viable platform for healthcare delivery with high patient and surgeon satisfaction. Most patients still prefer in-person visits for the post-pandemic future.

The development of low-cost, ultrasound-guided focused ultrasound (USgFUS) treatment platforms is expected to advance the adoption of microbubble (MB)-mediated brain therapy by improving access to the technology. Our group has designed and fabricated clinical-scale transmit/receive phased array systems for MB-mediated USgFUS brain therapy. Acoustic field simulations were carried out to optimize array element placement, and transducer scaffolds were constructed using 3D printing techniques. These devices have been employed for skull computed tomography-array registration, 3D spatial mapping of MB activity in vivo through ex-vivo human skullcaps via noninvasive aberration correction methods, and we have harnessed this spatiotemporal cavitation information to calibrate exposure levels for safe volumetric blood-brain barrier opening. At higher exposure levels, we have demonstrated the ability of 3D MB imaging data to predict the tissue damage volume distributions induced during nonthermal brain ablation. Ultrafast processing of acoustic emissions data has been shown to uncover MB dynamics hidden by conventional whole-burst temporal averaging, and can inform temporal undersampling strategies when millisecond-long tone bursts are applied. Machine learning approaches can assist with image-based classification of MB activity, which may result in finer control of the induced bioeffects. This talk will focus on our recent results obtained with a novel modular USgFUS phased array system.

Pharmacologic activation of branched-chain amino acid (BCAA) catabolism is protective in models of heart failure (HF). How protection occurs remains unclear, although a causative block in cardiac BCAA oxidation is widely assumed. Here, we use in vivo isotope infusions to show that cardiac BCAA oxidation in fact increases, rather than decreases, in HF. Moreover, cardiac-specific activation of BCAA oxidation does not protect from HF even though systemic activation does. Lowering plasma and cardiac BCAAs also fails to confer significant protection, suggesting alternative mechanisms of protection. Surprisingly, activation of BCAA catabolism lowers blood pressure (BP), a known cardioprotective mechanism. BP lowering occurred independently of nitric oxide and reflected vascular resistance to adrenergic constriction. Mendelian randomization studies revealed that elevated plasma BCAAs portend higher BP in humans. Together, these data indicate that BCAA oxidation lowers vascular resistance, perhaps in part explaining cardioprotection in HF that is not mediated directly in cardiomyocytes.

Determination of failure properties becomes extremely challenging when materials approach very low moduli ( $$< 100$$ kPa) and toughness values. New techniques are emerging to address these challenges in order to facilitate advancement of accurate tissue phantoms and medical diagnostics. We report on needle-induced ‘cavitations’ within a series of silicone elastomer formulations to demonstrate the ability of hydraulically-induced fracture morphology to differentiate fracture behavior in ultrasoft solids. We show, in accordance with previous results by Lefevre et al. (Int J Fract 192:1–23. https://doi.org/10.1007/s10704-014-9982-0 . ISSN 15732673, 2015), that cavities first grow elastically and then transition to a penny-shape with an associated ring crack. Further growth occurs predominantly at the ring crack, leading to variations in cavity anisotropy quantified via the cavity’s sphericity. Sphericity differentiates between materials of identical, ultralow modulus, but distinct formulation. We find that materials for which modulus is lowered by decreasing the crosslinker to pre-polymer ratio are tougher than materials in which modulus is lowered through the addition of unreactive silicone oil. We conclude that cavity shape provides a promising avenue for fracture energy determination and that the ultrasoft silicone/diluted-silicone system studied here provides a material platform for altering fracture properties while holding modulus constant.

Background: Asymptomatic, incidental extensor carpi ulnaris (ECU) tendon abnormalities are frequently noted on imaging studies of the wrist. The aim of this investigation was to determine if variations in gross tendon anatomy existed that could possibly account for these findings on MRI and ultrasound (US) imaging. Methods: The upper extremities of eleven (6 male and 5 female) formalin preserved cadavers were dissected and examined under loupe magnification with attention to the dorsal-ulnar wrist and hand and the ECU tendon. The tendons were inspected for anatomic variations, degenerative changes, and any other pathologies. The presence of intra-tendinous splits arising within the ECU tendon was noted and measured. The distances of the splits from the distal tendon insertion and the edge of the extensor retinaculum were recorded. Statistical correlations between age and the tendon splits were considered using R-squared to assess a linear regression. Results: 17 ECU tendons were dissected and examined, and 5 ECU tendons were excluded due to poor preservation of that upper extremity; all five were right sided upper extremities. Eleven of the 17 specimens demonstrated at least one split in the distal tendon: Seven had 1 split, 1 had 2 splits, and 3 had 3 splits. The mean length of the tendon split was 3.52 cm. The mean distance of the distal edge of the split to the tendon insertion site was 2.4 cm. A linear regression was calculated and showed no correlation between age and number of tendon splits. Conclusions: 64% of specimens showed a longitudinal split in the distal ECU tendon. The location of these frequent splits corresponds to imaging abnormalities on MRI and US in prior studies.

Though they share the similarity of inducing material failure at a crack tip, the cutting and tearing energies of soft materials cannot be quantitatively related to one another. One of the reasons for this lack of understanding comes from additional complications that arise during standard cutting techniques. Decades ago, Lake and Yeoh (Int J Fract 14(5):509–526 1978) described a natural rubber cutting method that uses a ‘Y-shaped’ sample geometry to mitigate several of these challenges, including minimizing friction and controlling the strain energy available to drive fracture. The latter, understood via a fracture mechanics framework, enables relative tuning between a tearing contribution to the cutting energy and a cutting contribution. In this manuscript, we extend Lake and Yeoh’s largely unreplicated results to softer, more highly deformable polydimethylsiloxane (PDMS) materials. The range of applicability of this technique to variations in material response, sample geometry, boundary conditions, and cutting rate is large. We utilize this flexibility to describe factors leading to the onset of a material-dependent, stick-slip cutting response, which occurs at low cutting rates and high tearing contributions. Furthermore, variation in cutting blade radius reveals a minimum cutting energy threshold even for blades with radii on the order of a few tens of nanometers. For blunter blades, cutting energy reflects the effects of material strain-stiffening. These results establish the Y-shaped cutting geometry as a useful tool in the study of soft fracture.

Background The abductor pollicis longus (APL) is classically described as inserting on the base of the first metacarpal. This study analyzed APL insertional anatomy and quantified the size of various elements of the extensor side of the thumb to determine associations with size and function. Methods Twenty-four formalin-preserved upper limbs were dissected. The insertional anatomy of the APL, extensor pollicis brevis, and extensor pollicis longus were characterized, and the capacity of APL tendon slips to perform palmar abduction of the first digit was quantified based on slip size and insertion. Results The mean number of APL tendon slips observed was 2.3. Abductor pollicis longus insertion sites included the base of the first metacarpal, trapezium, abductor pollicis brevis, and opponens pollicis. Only 4 specimens had a solitary metacarpal slip, while 83% of specimens had insertions onto at least 1 thenar muscle. A total of 62.5% of APL tendons exhibited some form of branching that we categorized into “Y” and “Z” patterns. In assessing palmar abduction capacity, we found that APL tendon slips inserting into the base of the first metacarpal were larger in cross-sectional area than nonmetacarpal slips and reproduced complete palmar abduction of the digit in the absence of nonmetacarpal slips. The abduction capacity of APL tendon slips was not correlated to the cross-sectional area. Conclusions There is significant variability in APL tendon slips, branching patterns, and insertional anatomy. These findings provide further understanding of the function of the APL and its surgical implications.

Supplemental material, sj-docx-1-han-10.1177_1558944721999734 for The Variable Insertional Anatomy of the Abductor Pollicis Longus: Functional Relevance and Relationship to Adjacent Thumb Extensors by Shruthi Deivasigamani, Ali Azad and S. Steven Yang in HAND

Background An allergic reaction may rarely cause a painful or stiff total knee arthroplasty (TKA). However, no consensus diagnostic criteria for TKA immune failure exist. Lymphocyte transformation testing (LTT) measures immune sensitivity to various materials, but its role in diagnosing an allergic reaction to a TKA has not been established. This study compares TKA periprosthetic tissues in a) LTT-positive versus -negative patients and b) patients with conventional CoCrNi versus hypoallergenic implants. Methods Periprosthetic tissues from 26 revision cases of well-fixed, aseptic, but painful or stiff TKAs were analyzed. Twelve patients LTT positive for nickel (Ni) were matched as a cohort to 6 LTT-negative patients. In 4 patients LTT positive for Ni, tissue from first revision of CoCrNi implants was compared with tissue from subsequent revision of hypoallergenic implants. Histology was evaluated using the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) score. Results No correlation was found between LTT and any ALVAL score component. The mean total ALVAL score was 3.8 ± 1.5 for LTT-negative patients and 3.3 ± 1.2 for LTT-positive patients (P = .44). The mean total ALVAL score at revision of CoCrNi implants was 3.0 ± 1.8 compared with 5.8 ± 0.5 at rerevision of hypoallergenic implants (P = .053). Conclusion Periprosthetic TKA tissue reactions were indistinguishable between LTT-positive and -negative patients. LTT does not predict the periprosthetic tissue response. ALVAL scores of hypoallergenic revision implant tissue trended higher than primary CoCrNi implant tissue. A positive LTT may not indicate that a periprosthetic immune reaction is the cause of pain and stiffness after TKA. Level of Evidence 3, retrospective cohort study.