Postoperative Vitamin D Surveillance and Supplementation in Revision Total Knee Arthroplasty Patients: A Retrospective Cohort Analysis

This study was a retrospective cohort analysis of 20 patients who underwent 23 revision total knee arthroplasty procedures in a single geographic region of the United States from January 2015 to February 2023. We analyzed their 25-OH vitamin D levels preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and 2 years. We categorized their supplementation regimens by dose: none, low dose (1000 IU and below), medium dose (1001-5000 IU), and high dose (>5000 IU). We found that there was a high incidence of vitamin D deficiency in this patient population.

Association of Pharmacologic Treatment of Depression/Anxiety With Initial Patient-Reported Outcome Measures in Patients With Hip and Knee Osteoarthritis

INTRODUCTION

Depression and anxiety are common comorbidities that may exacerbate osteoarthritis (OA)-related pain. We aim to evaluate the effect of pharmacologic treatment of depression/anxiety on hip and knee patient-reported outcome measures (PROMs).

METHODS

A multi-institutional PROMs database was queried for patients with depression or anxiety and hip or knee OA who completed a PROMs questionnaire at an initial orthopaedic visit between January 2015 and March 2023. Data on demographics, comorbidities, and duration of pharmacologic treatment of depression/anxiety were obtained. Patients were stratified into three cohorts based on treatment duration. PROMs were compared across cohorts.

RESULTS

Two thousand nine hundred sixty patients who completed PROMs at their initial orthopaedic visit had both OA and depression/anxiety. One hundred thirty-four (4.5%) received pharmacologic treatment of depression/anxiety for < 1 year, versus 196 (6.6%) for more than 1 year. In unadjusted analyses, patients with pharmacologic treatment had significantly lower Patient-Reported Outcomes Measurement Information System (PROMIS)-Physical (39.8 [IQR 34.9, 44.9] vs 42.3 [37.4, 47.7], P < 0.001) and PROMIS-Mental (43.5 [36.3, 50.8] vs 48.3 [41.1, 53.3], P < 0.001) scores than those without treatment. After adjusting for demographics and comorbidities, only differences in PROMIS-Mental scores remained statistically significant, with pharmacologic treatment associated with lower scores (β = -2.26, 95% CI, [-3.29, -1.24], P < 0.001). On secondary analysis including duration of pharmacologic treatment, < 1 year of treatment was associated with significantly lower PROMIS-Mental scores than those not treated (β = -4.20, 95% CI [-5.77, -2.62], P < 0.001) while scores of patients with more than 1 year of treatment did not differ significantly from those without treatment.

CONCLUSION

:Our results indicate that pharmacologic treatment of depression/anxiety is associated with improved psychological health but not with improved physical symptoms related to OA. We observed a nonsignificant trend that patients with depression/anxiety who warrant pharmacologic treatment tend to have worse physical symptoms than those who do not; however, unadjusted analyses suggest this is a complex relationship beyond the isolated effect of pharmacologic treatment.

Predictors of reoperation and survival experience for primary total knee arthroplasty in young patients with degenerative and inflammatory arthritis

INTRODUCTION

While total knee arthroplasty (TKA) is typically implemented in patients > 65 years old, young patients may need to undergo TKA for pain relief and functional improvement. Current data are limited by older cohorts and short-term survival rates. This study aimed to examine a large sample size of patients with degenerative and inflammatory conditions who underwent primary TKA at a young (≤ 40) age to identify predictors of reoperation, as well 15-year survivorship.

MATERIALS AND METHODS

A retrospective study was performed on 77 patients (92 surgeries) who underwent primary TKA at ≤ 40 years old, between January 1990 and January 2020. Patient charts were reviewed and a multivariable logistic regression model identified independent predictors of reoperation. Kaplan-Meier analysis was employed to build survival curves and log-rank tests analyzed survival between groups.

RESULTS

Of the 77 patients, the median age at the time of surgery was 35.7 years (IQR: 31.2-38.7) and median follow-up time was 6.88 years. Twenty-one (22.8%) primary TKAs underwent 24 reoperations, most commonly due to stiffness (n = 9, 32.1%) and infection (n = 13, 46.4%) more significantly in the OA group (p = 0.049). There were no independent predictors of reoperation in multivariable analysis, and 15-year revision-free survivorship after TKA did not differ by indication (77.3% for OA/PTOA vs. 96.7% for autoimmune, p = 0.09) or between ≤ 30 and 31-40 year age groups (94.7% vs. 83.6%, p = 0.55).

CONCLUSIONS

In this cohort of patients ≤ 40 years old, revision-free survival was comparable to that reported in the literature for older TKA patients with osteoarthritis/autoimmune conditions (81-94% at 15-years). Though nearly a quarter of TKAs required reoperation and causes of secondary surgery differed between degenerative and inflammatory arthritis patients, there were no significant predictors of increased reoperation rate. Very young patients ≤ 30 years old did not have an increased risk of revision compared to those aged 31-40 years.

Racial and Ethnic Minority Patients Have Increased Complication Risks When Undergoing Surgery While Not Meeting Clinical Guidelines

BACKGROUND

Clinical guidelines for performing total joint arthroplasty (TJA) have not been uniformly adopted in practice because research has suggested that they may foster inequities in surgical access, potentially disadvantaging minority sociodemographic groups. The aim of this study was to assess whether undergoing TJA without meeting clinical guidelines affects complication risk and leads to disparities in postoperative outcomes.

METHODS

This retrospective cohort study evaluated the records of 11,611 adult patients who underwent primary TJA from January 1, 2010, to December 31, 2020, at an academic hospital network. Based on self-reported race and ethnicity, 89.5% of patients were White, 3.5% were Black, 2.9% were Hispanic, 1.3% were Asian, and 2.8% were classified as other. Patients met institutional guidelines for undergoing TJA if they had a hemoglobin A1c of <8.0% and a body mass index of <40 kg/m2 and were not currently smoking. A logistic regression model was utilized to identify factors associated with complications, and a mixed-effects model was utilized to identify factors associated with not meeting guidelines for undergoing TJA.

RESULTS

During the study period, 11% (1,274) of the 11,611 adults who underwent primary TJA did not meet clinical guidelines. Compared with the group who met guidelines, the group who did not had higher proportions of Black patients (3.2% versus 6.0%; p < 0.001) and Hispanic patients (2.7% versus 4.6%; p < 0.001). An increased risk of not meeting guidelines at the time of surgery was demonstrated among Black patients (odds ratio [OR], 1.60 [95% confidence interval (CI), 1.22 to 2.10]; p = 0.001) and patients insured by Medicaid (OR, 1.75 [95% CI, 1.26 to 2.44]; p = 0.001) or Medicare (OR, 1.22 [95% CI, 1.06 to 1.41]; p = 0.007). Patients who did not meet guidelines had a higher risk of reoperation than those who met guidelines (7.7% [98] versus 5.9% [615]; p = 0.017), including a higher risk of infection-related reoperation (3.1% [40] versus 1.4% [147]; p < 0.001).

CONCLUSIONS

We found that patients who underwent TJA despite not meeting institutional preoperative criteria had a higher risk of postoperative complications. These patients were more likely to be from racial and ethnic minority groups, to have a lower socioeconomic status, and to have Medicare or Medicaid insurance. These findings underscore the need for surgery-related shared decision-making that is informed by evidence-based guidelines in order to reduce complication burden.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reverse Fragility Index: Comparing Revision Rates Between Direct Anterior and Other Approaches in Total Hip Arthroplasty. A Systematic Review of Randomized Controlled Trials

BACKGROUND

Despite increasing adoption of the direct anterior (DA) approach in total hip arthroplasty (THA), uncertainty persists regarding its outcomes beyond the 1-year mark in comparison to other approaches. We used the reverse fragility index (RFI) to evaluate the robustness of reported findings in the literature.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs) comparing implant revision rates between DA and other approaches in THA, defined as all those different from DA. Our primary outcome was the RFI, which gauges the number of events needed for a nonsignificant result to become significant, in the revision rate between DA and other approaches. We also calculated the reverse fragility quotient by dividing the RFI by each study's sample size. Median values and interquartile ranges (IQRs) were displayed.

RESULTS

A total of 10 RCTs with a total of 971 patients were included. The median RFI was 5 (IQR, 4 to 5), indicating the study's results would be statistically significant if the outcomes of 5 patients in 1 treatment arm were reversed. The median reverse fragility quotient was 0.049 (IQR, 0.04 to 0.057), indicating that a change of outcome in 4.9% of patients would render the revision rate significant. The median number of patients lost to follow-up was 4 (IQR, 0 to 7). Of the 10 RCTs, 6 had more patients lost to follow-up than their respective RFI values.

CONCLUSIONS

Notable fragility was evidenced in most studies comparing DA to other approaches for THA. Surgeons should not solely rely on the P value to determine clinical significance and instead use multiple metrics.

LEVEL OF EVIDENCE

II.

The Association of Sacro-Femoro-Pubic Angle and Postoperative Dislocation Following Total Hip Arthroplasty

BACKGROUND

Spino-pelvic orientation may affect dislocation risk following total hip arthroplasty (THA). It can be measured on lateral lumbo-pelvic radiographs. The sacro-femoro-pubic (SFP) angle, measured on an antero-posterior (AP) pelvis radiograph, is a reliable proxy for pelvic tilt, a measurement of spino-pelvic orientation measured on a lateral lumbo-pelvic radiograph. The purpose of this study was to investigate the relationship between SFP angle and dislocation following THA.

METHODS

An Institutional Review Board-approved retrospective case-control study was conducted at a single academic center. We matched 71 dislocators (cases) to 71 nondislocators (controls) following THA performed by 1 of 10 surgeons between September 2001 and December 2010. Two authors (readers) independently calculated SFP angle from single preoperative AP pelvis radiographs. Readers were blinded to cases and controls. Conditional logistic regressions were used to identify factors differentiating cases and controls.

RESULTS

The data did not show a clinically relevant or statistically significant difference in SFP angles after adjusting for gender, American Society of Anesthesiologists classification, prosthetic head size, age at time of THA, measurement laterality, and surgeon.

CONCLUSION

We did not find an association between preoperative SFP angle and dislocation following THA in our cohort. Based on our data, SFP angle as measured on a single AP pelvis radiograph should not be used to assess dislocation risk prior to THA.

Patient-Specific Safe Zones for Acetabular Component Positioning in Total Hip Arthroplasty: Mathematically Accounting for Spinopelvic Biomechanics

BACKGROUND

Despite a growing understanding of spinopelvic biomechanics in total hip arthroplasty (THA), there is no validated approach for executing patient-specific acetabular component positioning. The purpose of this study was to (1) validate quantitative, patient-specific acetabular "safe zone" component positioning from spinopelvic parameters and (2) characterize differences between quantitative patient-specific acetabular targets and qualitative hip-spine classification targets.

METHODS

From 2,457 consecutive primary THA patients, 22 (0.88%) underwent revision for instability. Spinopelvic parameters were measured prior to index THA. Acetabular position was measured following index and revision arthroplasty. Using a mathematical proof, we developed an open-source tool translating a surgeon-selected, preoperative standing acetabular target to a patient-specific safe zone intraoperative acetabular target. Difference between the patient-specific safe zone and the actual component position was compared before and after revision. Hip-spine classification targets were compared to patient-specific safe zone targets.

RESULTS

Of the 22 who underwent revision, none dislocated at follow-up (4.6 [range, 1 to 6.9]). Patient-specific safe zone targets differed from prerevision acetabular component position by 9.1 ± 4.2° inclination/13.3 ± 6.7° version; after revision, the mean difference was 3.2 ± 3.0° inclination/5.3 ± 2.7° version. Differences between patient-specific safe zones and the median and extremes of recommended hip-spine classification targets were 2.2 ± 1.9° inclination/5.6 ± 3.7° version and 3.0 ± 2.3° inclination/7.9 ± 3.5° version, respectively.

CONCLUSION

A mathematically derived, patient-specific approach accommodating spinopelvic biomechanics for acetabular component positioning was validated by approximating revised, now-stable hips within 5° version and 3° inclination. These patient-specific safe zones augment the hip-spine classification with prescriptive quantitative targets for nuanced preoperative planning.

Short-to Mid-Term Survivorship of a Patient-specific Unicompartmental Knee Arthroplasty Implant Cast from a Three-Dimensional Printed Mold

The purpose of this study was to determine early survivorship and complication rates associated with the implantation of a new patient-specific unicompartmental knee implant cast from a three-dimensional (3D) printed mold, introduced in 2012. We retrospectively reviewed 92 consecutive patients who underwent unicompartmental knee arthroplasty (UKA) with a patient-specific implant cast from a 3D printed mold between September 2012 and October 2015. The early results of a patient-specific UKA implant were favorable in our cohort, with survivorship free from reoperation of 97% at an average 4.5 years follow-up. Future studies are necessary to investigate the long-term performance of this implant. Survivorship of a patient-specific unicompartmental knee arthroplasty implant cast from a 3D printed mold.

Are There More Radiolucent Lines in Patients Who Underwent Total Knee Arthroplasty With or Without a Tourniquet During Cementation at 5 to 8 Years After Surgery?

BACKGROUND

This study investigated the presence and progression of radiolucent lines (RLLs) after cemented total knee arthroplasty (TKA) with or without tourniquet use.

METHODS

There were 369 consecutive primary cemented TKAs with 5 to 8 years of follow-up. A tourniquet was used during component cementation in patients who underwent surgery from January 3, 2006, to March 31, 2010. No tourniquet was used from August 14, 2009, to October 14, 2014. There were 192 patients in the tourniquet group (TQ) and 177 patients in the no tourniquet group (NQ). Patient demographics, reoperations, and complications were recorded. RLLs were identified on anteroposterior, lateral, and skyline x-rays at 1, 2, and 5 to 8 years postoperatively using the modern knee society radiographic evaluation system. Demographics, reoperations, complications, and RLLs were compared. Age, sex, and body mass index were similar between groups. Mean tourniquet time in TQ was 11 minutes (range, 8 to 25).

RESULTS

The presence of RLLs differed between groups, with 65% of TQ knees having RLLs under any part of the prostheses versus 46% of NQ knees (P < .001). The progression of RLL >2 mm occurred in 26.0% of knees in TQ and 16.7% of knees in NQ (P = .028). There were 13 TKAs that underwent subsequent revision surgery. There was no statistically or clinically significant difference in revision rate between groups (7 revisions in TQ, 6 in NQ, P = .66).

CONCLUSION

Less RLLs were identified in NQ versus TQ. There were no statistically or clinically significant differences in revision rates between the NQ and TQ groups at 5 to 8 years.

Patterns and Persistence of Perioperative Plasma and Cerebrospinal Fluid Neuroinflammatory Protein Biomarkers After Elective Orthopedic Surgery Using SOMAscan

BACKGROUND

The neuroinflammatory response to surgery can be characterized by peripheral acute plasma protein changes in blood, but corresponding, persisting alterations in cerebrospinal fluid (CSF) proteins remain mostly unknown. Using the SOMAscan assay, we define acute and longer-term proteome changes associated with surgery in plasma and CSF. We hypothesized that biological pathways identified by these proteins would be in the categories of neuroinflammation and neuronal function and define neuroinflammatory proteome changes associated with surgery in older patients.

METHODS

SOMAscan analyzed 1305 proteins in blood plasma (n = 14) and CSF (n = 15) samples from older patients enrolled in the Role of Inflammation after Surgery for Elders (RISE) study undergoing elective hip and knee replacement surgery with spinal anesthesia. Systems biology analysis identified biological pathways enriched among the surgery-associated differentially expressed proteins in plasma and CSF.

RESULTS

Comparison of postoperative day 1 (POD1) to preoperative (PREOP) plasma protein levels identified 343 proteins with postsurgical changes ( P < .05; absolute value of the fold change [|FC|] > 1.2). Comparing postoperative 1-month (PO1MO) plasma and CSF with PREOP identified 67 proteins in plasma and 79 proteins in CSF with altered levels ( P < .05; |FC| > 1.2). In plasma, 21 proteins, primarily linked to immune response and inflammation, were similarly changed at POD1 and PO1MO. Comparison of plasma to CSF at PO1MO identified 8 shared proteins. Comparison of plasma at POD1 to CSF at PO1MO identified a larger number, 15 proteins in common, most of which are regulated by interleukin-6 (IL-6) or transforming growth factor beta-1 (TGFB1) and linked to the inflammatory response. Of the 79 CSF PO1MO-specific proteins, many are involved in neuronal function and neuroinflammation.

CONCLUSIONS

SOMAscan can characterize both short- and long-term surgery-induced protein alterations in plasma and CSF. Acute plasma protein changes at POD1 parallel changes in PO1MO CSF and suggest 15 potential biomarkers for longer-term neuroinflammation that warrant further investigation.

SLAMF7 engagement superactivates macrophages in acute and chronic inflammation

Macrophages regulate protective immune responses to infectious microbes, but aberrant macrophage activation frequently drives pathological inflammation. To identify regulators of vigorous macrophage activation, we analyzed RNA-seq data from synovial macrophages and identified SLAMF7 as a receptor associated with a superactivated macrophage state in rheumatoid arthritis. We implicated IFN-γ as a key regulator of SLAMF7 expression and engaging SLAMF7 drove a strong wave of inflammatory cytokine expression. Induction of TNF-α after SLAMF7 engagement amplified inflammation through an autocrine signaling loop. We observed SLAMF7-induced gene programs not only in macrophages from rheumatoid arthritis patients but also in gut macrophages from patients with active Crohn's disease and in lung macrophages from patients with severe COVID-19. This suggests a central role for SLAMF7 in macrophage superactivation with broad implications in human disease pathology.

Is It the Back or the Hip? Differentiating Lumbar Spine From Hip Pathologies: Key Points of Evaluation and Treatment

Disorders of the hip and spine commonly coexist and are difficult to disentangle. When they do occur together, the pathology is often referred to as hip-spine syndrome. When hip-spine syndrome is suspected, it is critically important to properly identify the relative contributions that the hip and spine each provide to a patient's overall clinical presentation. To focus on the incorrect anatomic site would be a disservice to the patient. The interconnectivity of hip and spine pathology, the various clinical presentations of the most commonly seen hip and spine disorders, the broad differential and suggested workup that should be considered for such patients, the various treatment modalities available, and the clinical predictors and expected outcomes for patients with hip-spine syndrome are important factors for review.

Correlation Between Patient-Reported Outcome Measures and Health Insurance Provider Types in Patients with Hip Osteoarthritis

BACKGROUND

Patient-reported outcome measures (PROMs) are frequently utilized to assess patient perceptions of health and function. Numerous factors influence self-reported physical and mental health outcome scores. The purpose of this study was to examine if an association exists between insurance payer type and baseline PROM scores in patients diagnosed with hip osteoarthritis.

METHODS

We retrospectively reviewed the baseline PROM scores of 5,974 patients diagnosed with hip osteoarthritis according to the International Classification of Diseases, Tenth Revision (ICD-10) code within our institutional database from 2015 to 2020. We examined Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF10a), PROMIS Global-Mental, and PROMIS Global-Physical scores. Descriptive analyses, analysis of variance (ANOVA), analysis of covariance (ANCOVA), and post hoc analyses were utilized to assess variations in PROM scores across insurance type.

RESULTS

The mean age (and standard deviation) of the study population was 63.5 ± 12.2 years, and 55.7% of patients were female. The Medicaid cohort had a comparatively higher percentage of Black, Hispanic, and non-English-speaking patients and a lower median household income. The Charlson Comorbidity Index was highest in the Medicare and Medicaid insurance cohorts. Patients utilizing commercial insurance consistently demonstrated the highest baseline PROMs, and patients utilizing Medicaid consistently demonstrated the lowest baseline PROMs. Subsequent analyses found significantly poorer mean scores for the Medicaid cohort for all 4 PROMs when compared with the commercial insurance and Medicare cohorts. These score differences exceeded the minimal clinically important differences (MCIDs). For the PROMIS Global-Mental subscore, a significantly lower mean score was observed for the Workers' Compensation and motor vehicle insurance cohort when compared with the commercial insurance and Medicare cohort. This difference also exceeded the MCID.

CONCLUSIONS

PROM scores in patients with hip osteoarthritis varied among those with different insurance types. Variations in certain demographic and health indices are potential drivers of these observed baseline PROM differences. For patients with hip osteoarthritis, the use of PROMs for research, clinical, or quality-linked payment metrics should acknowledge baseline variation between patients with different insurance types.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Weight loss before total joint arthroplasty using a remote dietitian and mobile app: study protocol for a multicenter randomized, controlled trial

Background

The months prior to elective surgery may present an opportunity for patients to initiate behavior changes that will simultaneously ready them for surgery and improve their overall health status. An upcoming elective total joint arthroplasty (TJA) may serve as motivation for patients with severe obesity (body mass index [BMI]> 40 kg/m²) to lose weight, as it may optimize clinical outcomes following TJA and help them become eligible for TJA since some surgeons use a BMI of 40 kg/m² as a cut-off for offering surgery in an effort to optimize outcomes.

Methods

The purpose of this multicenter randomized, controlled trial is to assess the feasibility and efficacy of a 12-week remote dietitian (RD) supervised dietary and physical activity weight loss intervention and mobile app for 60 patients with severe obesity prior to undergoing TJA. Intervention participants will receive access to a smartphone app and connect with an RD who will contact these participants weekly or bi-weekly via video calls for up to nine video calls. Together, participants and RDs will set goals for lifestyle modifications, and RDs will check on progress towards achieving these goals using in-app tools such as food logs and text messages between video calls. All patients will be encouraged to lose at least 20 pounds with a goal BMI < 40 kg/m² after 12 weeks. Individuals randomized to the control group will receive clinical standard of care, such as nutritionist and/or physical therapy referrals. Outcome and demographic data will be collected from blood serology, chart review, mobile app user data, pre- and postintervention surveys, and phone interviews. The primary outcome measure will be weight change from baseline. Secondary outcome measures will include percentage of patients eligible to undergo TJA, number of sessions completed with dietitians, self-reported global health status (PROMIS Global Health scale), self-reported joint-specific pain and function (Knee injury and Osteoarthritis Outcome Score (KOOS) or Hip disability and Osteoarthritis Outcome Score (HOOS)), and serologies such as hemoglobin A1c, total lymphocyte count, albumin, and transferrin. Qualitative responses transcribed from phone interviews about the intervention will also be analyzed.

Discussion

This will be the first study to assess pre-operative weight loss in patients with severe obesity anticipating orthopaedic surgery using an RD and mobile app intervention aimed at helping patients become eligible for TJA.

Trial registration

Registered on 1 April 2020 at Clincialtrials.gov. Trial number is NCT04330391.

Association Between Preoperative Radiographic Severity of Osteoarthritis and Patient-Reported Outcomes of Total Knee Replacement

The goal of this study was to investigate the association between preoperative radiographic severity of knee osteoarthritis (OA) and patient-reported outcomes following total knee replacement.

Notch signalling drives synovial fibroblast identity and arthritis pathology

The synovium is a mesenchymal tissue composed mainly of fibroblasts with a lining and sublining that surrounds the joints. In rheumatoid arthritis (RA), the synovial tissue undergoes marked hyperplasia, becomes inflamed and invasive and destroys the joint^1,2. Recently, we and others found that a subset of fibroblasts located in the sublining undergoes major expansion in RA and is linked to disease activity^3,4,5. However, the molecular mechanism by which these fibroblasts differentiate and expand in RA remains unknown. Here, we identified a critical role for NOTCH3 signaling in the differentiation of perivascular and sublining CD90(THY1)+ fibroblasts. Using single cell RNA-sequencing and synovial tissue organoids, we found that NOTCH3 signaling drives both transcriptional and spatial gradients in fibroblasts emanating from vascular endothelial cells outward. In active RA, NOTCH3 and NOTCH target genes are markedly upregulated in synovial fibroblasts. Importantly, genetic deletion of Notch3 or monoclonal antibody-blockade of NOTCH3 signaling attenuates inflammation and prevents joint damage in inflammatory arthritis. Our results indicate that synovial fibroblasts exhibit positional identity regulated by endothelium-derived Notch signaling and that this stromal crosstalk pathway underlies inflammation and pathology in inflammatory arthritis.

Obesity and leptin influence vitamin D metabolism and action in human marrow stromal cells

Obesity is associated with low serum 25-hydroxyvitamin D [s25(OH)D], high serum leptin, and generally high bone mineral density (BMD). Human Marrow Stromal Cells (hMSCs) differentiate to osteoblasts and are both a target and source of vitamin D metabolites in bone marrow. There is no information about the influence of obesity on vitamin D metabolism and osteoblastogenesis in hMSCs and little about direct effects of leptin on hMSCs. In this study, we tested the hypotheses that 1) obesity has an influence on the ex vivo constitutive expression of vitamin D-hydroxylase genes in hMSCs, and 2) recombinant human (rh) Leptin regulates the D-hydroxylases and promotes osteoblastogenesis in hMSCs. In a cohort of female subjects undergoing joint replacement surgery, the effects of Body Mass Index (BMI) and Fat Mass Index (FMI) on BMD T-scores and s25(OH)D were evaluated. hMSCs were isolated from bone tissues discarded during surgery. The direct effects of rh-Leptin on osteoblast differentiation and D-related genes in hMSCs were examined in vitro. There were positive correlations for BMD T-score of femoral neck and spine with BMI and FMI. Serum 25(OH)D levels in obese subjects were 71% of that in non-obese counterparts (p = 0.001). hMSCs from obese women had higher constitutive expression of CYP27A1/25-hydroxylase and vitamin D receptor. Those findings raised the mechanistic question of how obesity could influence vitamin D metabolism and osteoblast differentiation in hMSCs. Treating hMSCs with rh-Leptin in vitro significantly stimulated osteoblastogenesis. In addition, leptin downregulated CYP24A1 and upregulated CYP27B1, CYP27A1 and VDR, which play vital roles in vitamin D metabolism. Furthermore, co-treatment with leptin and vitamin D₃ metabolites promoted ALP activity compared with either alone. This research demonstrates links between obesity, vitamin D metabolism, and osteoblastogenesis by which leptin's direct effects on D-metabolism and osteoblast differentiation in hMSCs may protect bone from low s25(OH)D in obese subjects.

Using Cluster Analysis to Identify Patient Factors Linked to Differential Functional Gains After Total Knee Arthroplasty

BACKGROUND

The basis of poor outcomes following total knee arthroplasty (TKA) is multifactorial. Previous research aimed at predicting outcome following TKA focuses largely on outcomes measured between two specific time points (pre-to post-TKA). Analysis of outcomes measured over multiple time points (trajectory) may expose relationships between patients' characteristics and longitudinal outcome patterns that may otherwise remain obscured.

METHODS

The current study analyzed Short Form 36 Physical Component Score (PCS) trajectories of 656 patients composed of 3 time points over a 1-year period. Clusters were constructed utilizing MultiExperiment Viewer hierarchical clustering algorithm. Statistical significance of these clusters was assessed using MeV's built-in bootstrapping method. Patient characteristics of the resulting statistically conserved clusters were summarized and compared using Wilcoxon rank-sum test or chi-squared test as appropriate.

RESULTS

Two distinct clusters of outcome trajectory were identified. Cluster 1 included 550 patients (84%) who demonstrated persistent PCS improvement at 6 and 12 months. Cluster 2 included 106 patients (16%) who demonstrated decline in PCS at 6 months followed by improvement at 12 months. Cluster 1 achieved earlier success, greater absolute mental and physical health scores as compared to Cluster 2 (P < .05), and demonstrated higher baseline mental health scores, lower baseline PCS, and a significantly higher proportion of non-Hispanic Whites (P ≤ .05).

CONCLUSION

Cluster analysis identified distinct functional outcome trajectories following TKA. Specific differentiating patient factors were associated with differing trajectories. Future studies should focus on this method's ability to inform predictive models regarding patient outcomes.

Anesthesia and Analgesia Practices in Total Joint Arthroplasty: A Survey of the American Association of Hip and Knee Surgeons Membership

BACKGROUND

The purpose of this study is to survey the current analgesia and anesthesia practices used by total joint arthroplasty surgeon members of the American Association of Hip and Knee Surgeons (AAHKS).

METHODS

A survey of 28 questions was created and approved by the AAHKS Research Committee. The survey was distributed to all 2208 board-certified adult reconstruction surgeon members of AAHKS in November 2018.

RESULTS

There were 622 responses (28.2%) to the survey. A majority of respondents (93.2%, n = 576) use preemptive analgesia prior to total joint arthroplasty. Most respondents use a spinal for total knee arthroplasty (TKA) (74.4%) and total hip arthroplasty (THA) (72.6%). A peripheral nerve block is routinely used by 68.7% of respondents in primary TKA. Periarticular injection or local infiltration anesthesia is routinely used by 80.3% of respondents for both TKA and THA patients. The average number of opioid pills prescribed postoperatively after TKA is 49 pills (range 0-200) and after THA is 44 pills (range 0-200). Most surgeons (58%) expect that this prescription should last for 2 weeks. A majority of respondents (74.0%) use multimodal analgesics in addition to opioids.

CONCLUSION

There is no consensus regarding the optimal multimodal anesthetic and analgesic regimen for total joint arthroplasty among surveyed board-certified arthroplasty surgeon members of AAHKS. Understanding current practice patterns in anesthesia, analgesia, and opioid prescribing may serve as a platform for future work aimed at establishing best clinical practices of maximizing effective postoperative pain control and minimizing the risks associated with prescribing opioids.

The Role of Inflammation after Surgery for Elders (RISE) study: Study design, procedures, and cohort profile

Introduction

The Role of Inflammation after Surgery for Elders study correlates novel inflammatory markers measured in blood, cerebrospinal fluid (CSF) assays, and [¹¹C]-PBR28 positron-emission tomography imaging.

Methods

This study involved a prospective cohort design with patients who underwent elective hip and knee arthroplasty under spinal anesthesia. Sixty-five adults participated with their family members. Inflammatory biomarker assays were measured preoperatively on day 1 and postoperatively at one month.

Results

On average, participants were 75 years old, and 72% were female. 54% underwent total knee arthroplasty, and 46% underwent total hip arthroplasty. The mean Modified Mini-Mental State (3MS) Examination score was 89.3; four patients (6%) scored ≤77 points. Plasma assays were completed in 63 (97%) participants, cerebrospinal fluid assays in 61 (94%), and PET imaging in 44 (68%).

Discussion

This complex study presents an innovative effort to correlate peripheral and central inflammatory biomarkers before and after major surgery in older adults. Strengths include collecting concurrent blood, cerebrospinal fluid, and positron-emission tomography with detailed clinical characterization of delirium, cognition, and functional status.

•

We describe the methodology of the Role of Inflammation after Surgery for Elders Study.

•

This is a prospective cohort of elective hip/knee arthroplasty patients 70 years or older.

•

We examine inflammation in blood, cerebrospinal fluid and positron emission tomography.

•

We collect novel biomarkers preoperatively and one-month postoperatively.

•

There is clinical characterization of delirium, cognition and functional status.

Longitudinal Trajectories of Pain and Function Improvement Following Total Knee Replacement

Objective

Up to 30% of patients experience persistent pain and functional limitations following total knee replacement (TKR). Rapid symptom relief in the early postoperative period may be linked to longer‐term outcome improvements. We sought to identify early improvement trajectories and to identify risk factors for suboptimal outcomes.

Methods

We used data from the Adding Value in Knee Arthroplasty (AViKA) Cohort study, a prospective longitudinal study of patients with knee osteoarthritis who underwent TKR. We assessed pain and function using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). We used group‐based trajectory modeling to identify distinct patterns of pain and function improvement over 6 months. We assessed the association between these early improvement trajectories and 24‐month outcomes, including pain, function, and satisfaction.

Results

We analyzed data from 107 subjects. Mean baseline WOMAC pain and function scores were 42 (SD 17) and 44 (SD 15), respectively (0‐100; 100 = worst). We identified two pain‐improvement trajectories (suboptimal vs optimal improvement) and two function‐improvement trajectories (suboptimal vs optimal improvement). Greater pain catastrophizing, worse mental health status, and use of a supportive device prior to TKR were associated with being in a suboptimal trajectory. Recipients of TKR in the suboptimal trajectories had higher pain, high functional disability, and lower satisfaction at 24 months post‐TKR.

Conclusion

Patients with slower improvement over the first 6 months post‐TKR had worse outcomes at 24 months, suggesting that this early postoperative period may represent a window during which interventions aimed at speeding recovery may improve long‐term TKR outcomes.

Satisfaction Rates and Quality of Life Changes Following Total Knee Arthroplasty in Age-Differentiated Cohorts

BACKGROUND

Comparisons of satisfaction rates following total knee arthroplasty (TKA) among large, age-differentiated, rigorously matched cohorts are lacking. Therefore, we compared satisfaction rates following TKA in large, age-differentiated, propensity score-matched cohorts.

METHODS

We identified primary TKAs performed for non-inflammatory arthritis in patients of ages 18-55 or 65-75, yielding 529 younger and 2001 older patients. Patient-reported outcomes were recorded pre-operatively and 2 years post-operatively. 1:1 propensity score matching between groups yielded 529 patient pairs. Matching was based on gender, body mass index, American Society of Anesthesiologists grade, Charlson Comorbidity Index, and Short Form 12 Mental Health Component score. Outcomes were compared between matched groups using t-test and Wilcoxon rank-sum test.

RESULTS

Satisfaction with knee surgery was 86% among younger patients and 91% among older patients. Distribution of satisfaction responses was shifted toward greater satisfaction in older patients (P < .001). Overall quality of life (QOL) improvement was 91% among younger patients and 96% among older patients. Pre-operative and post-operative knee-related QOL was better among older patients (P < .0001). Post-operative global health-related QOL was equivalent between groups based on Short Form 12 Physical Component Score and Mental Health Component score (P = .6646 and P = .5705, respectively) and QOL improvement questionnaires (P = .181). Younger patients reported greater knee-related dysfunction and higher activity levels pre-operatively and post-operatively (P ≤ .0002).

CONCLUSION

Satisfaction with knee surgery was over 85% regardless of age. Younger patients perceived more knee-related dysfunction and dissatisfaction after surgery despite higher levels of self-reported activity pre-operatively and post-operatively.

Utilizing Dual Mobility Components for First-Time Revision Total Hip Arthroplasty for Instability

BACKGROUND

Dislocation following total hip arthroplasty (THA) remains a significant clinical problem. Few studies have focused on the use of dual mobility (DM) components in the setting of first-time revision for instability following THA. Here, we investigate patient outcomes following first-time revision THA with DM components for a diagnosis of instability.

METHODS

Institution-wide revision THAs using DM components performed between 2010 and 2013 were identified. Chart review identified 40 patients with average 3-year follow-up who had undergone first-time revision for instability, defined as instability after primary THA. Etiology of instability was classified by Wera type. Patient demographics, medical co-morbidities, re-dislocations, and re-revisions were recorded. Component position and leg-length discrepancy were measured on pre-operative and post-operative radiographs when available. Utilizing Student's t-test or Fisher's exact test, we analyzed differences between those who endured recurrent dislocation and those who did not.

RESULTS

Recurrent dislocation occurred in 2 patients (5%). Both patients underwent re-revision for recurrent instability and carried diagnoses of instability of unresolved etiology. Two patients underwent re-revision for reasons unrelated to the DM construct. All-cause re-revision rate at final follow-up was therefore 10% (4 patients). No medical, demographic, or radiographic factors were significantly associated with risk of recurrent instability (P > .05).

CONCLUSION

The use of DM components for first-time revision THA for a diagnosis of instability carried a re-dislocation rate of 5% and an all-cause re-revision rate of 10% at average 3-year follow-up. Instability of unresolved etiology was associated with re-dislocation following revision surgery.

Dual-Mobility vs Fixed-Bearing Total Hip Arthroplasty in Patients Under 55 Years of Age: A Single-Institution, Matched-Cohort Analysis

BACKGROUND

Prosthetic dislocation of total hip arthroplasty (THA) is a common cause for revision surgery. Dual-mobility (DM) bearings were introduced to mitigate complications; however, their performance in younger patients is unknown. This study compared results of patients <55 years of age with DM vs fixed-bearing (FB) primary THA.

METHODS

Our total joint registry was used to evaluate primary THA patients <55 years of age, and then, an age-matched comparative analysis was performed for 136 THAs using third-generation highly cross-linked polyethylene DM bearings and 136 THAs using FB from the same manufacturer with mean follow-up of 3.2 and 3.4 years, respectively. Mean age at surgery was 48.4 and 48.5 years, respectively. There was no difference in gender distribution. Incidence of complications (eg, dislocation) was evaluated and compared statistically. Patient-reported outcomes using the Modified Harris Hip Score were available. Normally distributed continuous data were compared using the Student t test, and discrete data were compared using the Fisher exact test (P < .05).

RESULTS

There were no dislocations or intraprosthetic dissociations (0%) in the DM group and 7 (5.1%) dislocations in the FB group (P = .01) at the mean follow-up of 3 years postoperatively. Two of the 7 unstable patients in the FB cohort were revised for recurrent instability (1.5%). There was no difference in postoperative Modified Harris Hip Score between the DM (87.2 ± 16.6) and the control cohorts (87.9 ± 13.7; P = .78).

CONCLUSION

DM bearings in patients <55 years of age show excellent results for prosthetic stability when compared with patients who undergo FB.