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 surround the joints. In rheumatoid arthritis the synovial tissue undergoes marked hyperplasia, becomes inflamed and invasive, and destroys the joint1,2. It has recently been shown that a subset of fibroblasts in the sublining undergoes a major expansion in rheumatoid arthritis that is linked to disease activity3-5; however, the molecular mechanism by which these fibroblasts differentiate and expand is unknown. Here we identify a critical role for NOTCH3 signalling in the differentiation of perivascular and sublining fibroblasts that express CD90 (encoded by THY1). Using single-cell RNA sequencing and synovial tissue organoids, we found that NOTCH3 signalling drives both transcriptional and spatial gradients-emanating from vascular endothelial cells outwards-in fibroblasts. In active rheumatoid arthritis, NOTCH3 and Notch target genes are markedly upregulated in synovial fibroblasts. In mice, the genetic deletion of Notch3 or the blockade of NOTCH3 signalling attenuates inflammation and prevents joint damage in inflammatory arthritis. Our results indicate that synovial fibroblasts exhibit a positional identity that is regulated by endothelium-derived Notch signalling, and that this stromal crosstalk pathway underlies inflammation and pathology in inflammatory arthritis.

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.

The Evolution of Implant Design Decreases the Incidence of Lateral Release in Primary Total Knee Arthroplasty.

BACKGROUND: Appropriate balancing of the patellofemoral joint (PFJ) using a lateral release can help to prevent patellar instability in total knee arthroplasty (TKA). Contemporary total knee implant designs are characterized by enhanced trochlear geometry more similar to native knee anatomy to minimize instability and reduce utilization of a lateral release. METHODS: We retrospectively reviewed consecutive TKA cases from a single senior surgeon's practice with 3 successive total knee designs: the Press-Fit Condylar (PFC), the Sigma, and the ATTUNE (DePuy, Warsaw, IN). We evaluated the use of lateral release with each implant type to determine if design changes have improved patellar stability, reducing the need for lateral release. We used multivariate analysis to determine the association between implant type and lateral release, adjusting for age, sex, preoperative alignment, and bearing type. RESULTS: We evaluated 1991 records of primary TKAs performed from 1980-2015. As compared with the ATTUNE, the adjusted odds of lateral release were greater for patients receiving PFC implants (Odds ratio [OR] 6.35, 95% confidence interval [CI] 3.85,10.49) and Sigma implants (OR 2.02, 95% CI 1.26, 3.23). In addition, fixed bearing implants were associated with greater adjusted odds of lateral release (OR 1.80, 95% CI 1.24, 2.62). CONCLUSION: We found that older knee implants were associated with higher use of lateral release, with successive designs the need for lateral release to balance the PFJ decreased. Continued design improvements to match the native knee anatomy may further improve the stability of the PFJ in future designs.

Predictors of Patient-Reported Outcomes of Total Joint Arthroplasty in a Developing Country.

BACKGROUND: In response to the growing burden of joint disease, developing countries are starting to create their own total joint arthroplasty (TJA) programs. To date, there has been limited research on predictors of TJA outcomes in a developing country. This investigation uses patient-reported outcome measures collected by a medical mission to assess predictors of TJA outcomes in the Dominican Republic. METHODS: Baseline and postoperative information from 156 of the mission's recipients of hip and knee TJA was used. Demographics were abstracted from clinical notes, and self-reported pain and functional status were assessed using Western Ontario and McMaster University Osteoarthritis Index and Short-Form 36 measures. Bivariate analysis identified variables to include in multivariable regression models of factors associated with function and pain outcomes and improvement in these domains 1 or 2 years postoperatively. RESULTS: The cohort had a mean age of 61.3 years, 82% were female, 79% had total knee arthroplasty, and 42% of the procedures were bilateral. In multivariate analyses, at P < .05, male sex, better preoperative function, and use of bilateral procedure were associated with better functional outcome. Male sex and worse preoperative pain were associated with better pain outcome. Worse preoperative pain and function, as well as bilateral surgery were associated with greater improvement in function. Additionally, a greater number of bothersome joints was associated with greater pain reduction. CONCLUSION: Our findings of better follow-up pain scores among patients with worse pain preoperatively and better functional improvement among those undergoing bilateral replacements contrast with study results from developed countries. The explanations for these observations merit further study.

Cruciate-retaining TKA is an option in patients with prior patellectomy.

BACKGROUND: The recommendation for using posterior-stabilized (PS) implants in patellectomy patients undergoing total knee arthroplasty (TKA) is based on older case series with heterogeneous patient populations. The use of cruciate-retaining implants in these patients has not been evaluated with more contemporary implant designs. QUESTIONS/PURPOSES: The purpose of this study was to evaluate the survivorship and functional outcomes (Knee Society score, presence of an extensor lag, and range of motion) of cruciate-retaining (CR) TKA in patients with prior patellectomy. METHODS: Between 1986 and 2012, we performed 27 CR TKAs in 25 patients after patellectomy. Of those, 23 CR TKAs in 21 patients were available for followup at a minimum of 2 years (mean, 11.2 years; range, 2.3-25.1 years). In this retrospective study, we queried a prospectively maintained database to assess functional outcomes and survivorship. RESULTS: Aseptic loosening-free survival was 100% at 5 and 10 years, and survival with revision for any reason as the outcome was 96% at 5 years (95% confidence interval [CI], 87.7%-100%) and 84% at 10 years (95% CI, 69.5%-100%). One patient was revised for aseptic loosening at 10.2 years postoperatively. Mean Knee Society scores improved from 36±13 preoperatively to 92±9.6 at followup. Extensor lag was present in seven patients preoperatively and only three at followup. Average knee flexion at followup was 112°±12.5°. CONCLUSIONS: In this study we found good long-term survivorship and functional outcomes with a CR implant design in patients following patellectomy. Earlier studies have favored PS over CR implants for patients with patellectomies. We believe this series suggests that CR TKA is indeed an option in patients with patellectomy. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Can therapy dogs improve pain and satisfaction after total joint arthroplasty? A randomized controlled trial.

BACKGROUND: The use of animals to augment traditional medical therapies was reported as early as the 9th century but to our knowledge has not been studied in an orthopaedic patient population. The purpose of this study was to evaluate the role of animal-assisted therapy using therapy dogs in the postoperative recovery of patients after THA and TKA. QUESTIONS/PURPOSES: We asked: (1) Do therapy dogs have an effect on patients' perception of pain after total joint arthroplasty as measured by the VAS? (3) Do therapy dogs have an effect on patients' satisfaction with their hospital stay after total joint arthroplasty as measured by the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS)? METHODS: A randomized controlled trial of 72 patients undergoing primary unilateral THA or TKA was conducted. Patients were randomized to a 15-minute visitation with a therapy dog before physical therapy or standard postoperative physical therapy regimens. Both groups had similar demographic characteristics. Reduction in pain was assessed using the VAS after each physical therapy session, beginning on postoperative Day 1 and continuing for three consecutive sessions. To ascertain patient satisfaction, the proportion of patients selecting top-category ratings in each subsection of the HCAHPS was compared. RESULTS: Patients in the treatment group had lower VAS scores after each physical therapy session with a final VAS score difference of 2.4 units (animal-assisted therapy VAS, 1.7; SD, 0.97 [95% CI, 1.4-2.0] versus control VAS, 4.1; SD, 0.97 [95% CI, 3.8-4.4], p<0.001) after the third physical therapy session. Patients in the treatment group had a higher proportion of top-box HCAHPS scores in the following fields: nursing communication (33 of 36, 92% [95% CI, 78%-98%] versus 69%, 25 of 36 [95% CI, 52%-84%], p=0.035; risk ratio, 1.3 [95% CI of risk ratio, 1.0-1.7]; risk difference, 23% [95% CI of risk difference, 5%-40%]), pain management (34 of 36, 94% [95% CI, 81%-99%], versus 26 of 36, 72% [95% CI, 55%-86%], p=0.024; risk ratio, 1.3 [95% CI of risk ratio, 1.1-1.6]; risk difference, 18% [95% CI of risk difference, 5%-39%]). The overall hospital rating also was greater in the treatment group (0-10 scale) (9.6; SD, 0.7 [95% CI, 9.3-9.8] versus 8.6, SD, 0.9 [95% CI, 8.3-8.9], p<0.001). CONCLUSIONS: The use of therapy dogs has a positive effect on patients' pain level and satisfaction with hospital stay after total joint replacement. Surgeons are encouraged to inquire about the status of volunteer-based animal-assisted therapy programs in their hospital as this may provide a means to improve the immediate postoperative recovery for a select group of patients having total joint arthroplasty. LEVEL OF EVIDENCE: Level II, randomized controlled study. See Instructions for Authors for a complete description of levels of evidence.

Effect of smoking and soft tissue release on risk of revision after total knee arthroplasty: a case- control study.

BACKGROUND: Increasing utilization of primary total knee arthroplasty (TKA) is projected to expand demand for revision TKA. Revision TKAs are procedurally complex and incur high costs on our financially constrained healthcare system. The purpose of this study was to use a case-control design to identify factors predisposing to revision TKA, particularly demographic, clinical and perioperative technical factors. METHODS: We conducted a case control study to investigate patient, surgical and perioperative factors associated with greater risk of revision TKA. We included patients who received TKA at a tertiary center between 1996 and 2009. Cases (patients that had primary and revision TKA) were matched to controls (patients with primary TKA that was not revised) in a 1:2 ratio and risk of revision examined using conditional logistic regression. RESULTS: We identified 146 cases and 290 controls. Patient factors independently associated with revision included male sex (OR 1.73; 95% CI 1.06-2.81) and smoking (OR 2.87; 1.33-6.19). Older age was associated with decreased risk (OR 0.83 per 5-year increment; 95% CI 0.75-0.92). Lateral release was the only technical factor associated with revision (OR 1.92; 1.07-3.43). CONCLUSIONS: In this case control study younger patient age, male gender, soft tissue release and active smoking status were associated with increased revision risk. Although we do not know whether the risk of smoking arises from short- or long-term exposure, smoking cessation prior to TKA should be considered as an intervention for decreasing revision risk.

Participation in physical activity in patients 1-4 years post total joint replacement in the Dominican Republic.

BACKGROUND: To address both the growing burden of joint disease and the gaps in medical access in developing nations, medical relief organizations have begun to launch programs to perform total joint replacement (TJR) on resident populations in developing countries. One outcome of TJR of particular interest is physical activity (PA) since it is strongly linked to general health. This study evaluates the amount of postoperative participation in PA in low-income patients who received total joint replacement in the Dominican Republic and identifies preoperative predictors of postoperative PA level. METHODS: We used the Yale Physical Activity Survey (YPAS) to assess participation in postoperative PA 1-4 years following total knee or hip replacement. We compared the amount of aerobic PA reported by postoperative TJR patients with the levels of PA recommended by the CDC and WHO. We also analyzed preoperative determinants of postoperative participation in aerobic PA in bivariate and multivariate analyses. RESULTS: 64 patients out of 170 eligible subjects (52/128 TKR and 14/42 THR) who received TJR between 2009-2012 returned for an annual follow-up visit in 2013, with a mean treatment-to-follow-up time of 2.1 years. 43.3% of respondents met CDC/WHO criteria for sufficient participation in aerobic PA. Multivariate analyses including data from 56 individuals identified that patients who were both younger than 65 and at least two years postoperative had an adjusted mean activity dimensions summary index (ADSI) 22.9 points higher than patients who were 65 or older and one year postoperative. Patients who lived with friends or family had adjusted mean ADSI 17.2 points higher than patients living alone. Patients who had the most optimistic preoperative expectations of outcome had adjusted mean ADSI scores that were 19.8 points higher than those who were less optimistic. CONCLUSION: The TJR patients in the Dominican cohort participate in less PA than recommended by the CDC/WHO. Additionally, several associations were identified that potentially affect PA in this population; specifically, participants who are older than 65, recently postoperative, less optimistic about postoperative outcomes and who live alone participate in less PA.

Associations between preoperative functional status and functional outcomes of total joint replacement in the Dominican Republic.

OBJECTIVE: In developed countries, the functional status scores of patients with poor preoperative scores undergoing total joint replacement (TJR) improve more following TJR than those for patients with better preoperative scores. However, those with better preoperative scores achieve the best postoperative functional outcomes. We determined whether similar associations exist in a developing country. METHODS: Dominican patients undergoing total hip or knee replacement completed WOMAC and SF-36 surveys preoperatively and at 12-month follow-up. Patients were stratified into low-, medium- and high-scoring preoperative groups based on their preoperative WOMAC function scores. We examined the associations between the baseline functional status of these groups and two outcomes-improvement in functional status over 12 months and functional status at 12 months-using analysis of variance with multivariable linear regression. RESULTS: Patients who scored the lowest preoperatively made the greatest gains in function and pain relief following their TJRs. However, there were no significant differences in pain or function at 12-month follow-up between patients who scored low and those who scored high on preoperative WOMAC and SF-36 surveys. CONCLUSION: Patients with poor preoperative functional status had greater improvement but similar 12-month functional outcomes compared with patients who had a higher level of function before surgery. These results suggest that a policy of focusing scarce resources on patients with worse functional status in developing countries may optimize improvement following TJR without threatening functional outcome. Additional research is needed to confirm these findings in other developing countries and to understand why these associations vary between patients in the Dominican Republic and patients from developed countries.

Enhancing the quality of international orthopedic medical mission trips using the blue distinction criteria for knee and hip replacement centers.

BACKGROUND: Several organizations seek to address the growing burden of arthritis in developing countries by providing total joint replacements (TJR) to patients with advanced arthritis who otherwise would not have access to these procedures. Because these mission trips operate in resource poor environments, some of the features typically associated with high quality care may be difficult to implement. In the U.S., many hospitals that perform TJRs use the Blue Cross/Shield's Blue Distinction criteria as benchmarks of high quality care. Although these criteria were designed for use in the U.S., we applied them to Operation Walk (Op-Walk) Boston's medical mission trip to the Dominican Republic. Evaluating the program using these criteria illustrated that the program provides high quality care and, more importantly, helped the program to find areas of improvement. METHODS: We used the Blue Distinction criteria to determine if Op-Walk Boston achieves Blue Distinction. Each criterion was grouped according to the four categories included in the Blue Distinction criteria--"general and administrative", "structure", "process", or "outcomes and volume". Full points were given for criteria that the program replicates entirely and zero points were given for criteria that are not replicated entirely. Of the non-replicated criteria, Op-Walk Boston's clinical and administrative teams were asked if they compensate for failure to meet the criterion, and they were also asked to identify barriers that prevent them from meeting the criterion. RESULTS: Out of 100 possible points, the program received 71, exceeding the 60-point threshold needed to qualify as a Blue Distinction center. The program met five out of eight "required" criteria and 11 out of 19 "informational" criteria. It scored 14/27 in the "general" category, 30/36 in the "structure" category, 17/20 in the "process" category, and 10/17 in the "outcomes and volume" category. CONCLUSION: Op-Walk Boston qualified for Blue Distinction. Our analysis highlights areas of programmatic improvement and identifies targets for future quality improvement initiatives. Additionally, we note that many criteria can only be met by hospitals operating in the U.S. Future work should therefore focus on creating criteria that are applicable to TJR mission trips in the context of developing countries.

Obesity & hypertension are determinants of poor hemodynamic control during total joint arthroplasty: a retrospective review.

BACKGROUND: Proper blood pressure control during surgical procedures such as total joint arthroplasty (TJA) is considered critical to good outcome. There is poor understanding of the pre-operative risk factors for poor intra-operative hemodynamic control. The purpose of this study is to identify risk factors for poor hemodynamic control during TJA. METHODS: We performed a retrospective cohort analysis of 118 patients receiving TJA in the Dominican Republic. We collected patient demographic and comorbidity data. We developed an a priori definition for poor hemodynamic control: 1) Mean arterial pressure (MAP) <65% of preoperative MAP or 2) MAP >135% of preoperative MAP. We performed bivariate and multivariate analyses to identify risk factors for poor hemodynamic control during TJA. RESULTS: Hypertension was relatively common in our study population (76 of 118 patients). Average preoperative mean arterial pressure was 109.0 (corresponding to an average SBP of 149 and DBP of 89). Forty-nine (41.5%) patients had intraoperative blood pressure readings consistent with poor hemodynamic control. Based on multi-variable analysis preoperative hypertension of any type (RR 2.9; 95% CI 1.3-6.3) and an increase in BMI (RR 1.2 per 5 unit increase; 95% CI 1.0-1.5) were significant risk factors for poor hemodynamic control. CONCLUSIONS: Preoperative hypertension and being overweight/obese increase the likelihood of poor blood pressure control during TJA. Hypertensive and/or obese patients warrant further attention and medical optimization prior to TJA. More work is required to elucidate the relationship between these risk factors and overall outcome.

A broad screen for targets of immune complexes decorating arthritic joints highlights deposition of nucleosomes in rheumatoid arthritis.

Deposits of Ig and complement are abundant in affected joints of patients with rheumatoid arthritis (RA) and in animal models of RA in which antibodies are demonstrably pathogenic. To identify molecular targets of the Igs deposited in arthritic joints, which may activate local inflammation, we used a combination of mass spectrometry (MS) and protein microarrays. Immune complexes were affinity-purified from surgically removed joint tissues of 26 RA and osteoarthritis (OA) patients. Proteins complexed with IgG were identified by proteomic analysis using tandem MS. A striking diversity of components of the extracellular matrix, and some intracellular components, copurified specifically with IgG from RA and OA tissues. A smaller set of autoantigens was observed only in RA eluates. In complementary experiments, IgG fractions purified from joint immune complexes were tested on protein microarrays against a range of candidate autoantigens. These Igs bound a diverse subset of proteins and peptides from synovium and cartilage, different from that bound by normal serum Ig. One type of intracellular protein detected specifically in RA joints (histones H2A/B) was validated by immunohistology and found to be deposited on the cartilage surface of RA but not OA joints. Thus, autoantibodies to many determinants (whether deposited as "neoantigens" or normal constituents of the extracellular matrix) have the potential to contribute to arthritic inflammation.

Synovial fibroblasts self-direct multicellular lining architecture and synthetic function in three-dimensional organ culture.

OBJECTIVE: To define the intrinsic capacity of fibroblast-like synoviocytes (FLS) to establish a 3-dimensional (3-D) complex synovial lining architecture characterized by the multicellular organization of the compacted synovial lining and the elaboration of synovial fluid constituents. METHODS: FLS were cultured in spherical extracellular matrix (ECM) micromasses for 3 weeks. The FLS micromass architecture was assessed histologically and compared with that of dermal fibroblast controls. Lubricin synthesis was measured via immunodetection. Basement membrane matrix and reticular fiber stains were performed to examine ECM organization. Primary human and mouse monocytes were prepared and cocultured with FLS in micromass to investigate cocompaction in the lining architecture. Cytokine stimuli were applied to determine the capacity for inflammatory architecture rearrangement. RESULTS: FLS, but not dermal fibroblasts, spontaneously formed a compacted lining architecture over 3 weeks in the 3-D ECM micromass organ cultures. These lining cells produced lubricin. FLS rearranged their surrounding ECM into a complex architecture resembling the synovial lining and supported the survival and cocompaction of monocyte/macrophages in the neo-lining structure. Furthermore, when stimulated by cytokines, FLS lining structures displayed features of the hyperplastic rheumatoid arthritis synovial lining. CONCLUSION: This 3-D micromass organ culture method demonstrates that many of the phenotypic characteristics of the normal and the hyperplastic synovial lining in vivo are intrinsic functions of FLS. Moreover, FLS promote survival and cocompaction of primary monocytes in a manner remarkably similar to that of synovial lining macrophages. These findings provide new insight into inherent functions of the FLS lineage and establish a powerful in vitro method for further investigation of this lineage.

Underestimated fracture probability in patients with unilateral hip osteoarthritis as calculated by FRAX.

Osteoporosis (OP) and osteoarthritis (OA) are age-related diseases often considered to be mutually exclusive. We previously found that 25% of women with advanced OA had occult OP and that femoral neck (FN) bone mineral density (BMD) T-scores were significantly higher for osteoarthritic vs contralateral hips. The FRAX calculator incorporates clinical risk factors and FN BMD T-score to estimate 10-yr total fracture probability and hip fracture probability. In 35 women and men aged 41 yr or older with unilateral hip OA scheduled for hip replacement, we tested whether FRAX fracture probability is underestimated when using data for the OA rather than the contralateral hip. There were between-hip differences for FN BMD T-score (p<0.0001), total fracture probability (p =0.0004), and hip fracture probability (p =0.0009). Use of FN BMD T-scores resulted in OP treatment recommendations for 0% and 11% of subjects compared with 11% and 17% for total fracture probability and hip fracture probability, respectively. In 6-11% of subjects in this series, the FRAX calculator underestimated fracture probability with data for the OA hip. With the increased use of FRAX in clinical use, these data suggest that measurement of BMD at the contralateral hip may yield higher calculated FRAX total and hip fracture probabilities.

Patient disease perceptions and coping strategies for arthritis in a developing nation: a qualitative study.

BACKGROUND: There is little prior research on the burden of arthritis in the developing world. We sought to document how patients with advanced arthritis living in the Dominican Republic are affected by and cope with their disease. METHODS: We conducted semi-structured, one-to-one interviews with economically disadvantaged Dominican patients with advanced knee and/or hip arthritis in the Dominican Republic. The interviews, conducted in Spanish, followed a moderator's guide that included topics such as the patients' understanding of disease etiology, their support networks, and their coping mechanisms. The interviews were audiotaped, transcribed verbatim in Spanish, and systematically analyzed using content analysis. We assessed agreement in coding between two investigators. RESULTS: 18 patients were interviewed (mean age 60 years, median age 62 years, 72% women, 100% response rate). Patients invoked religious and environmental theories of disease etiology, stating that their illness had been caused by God's will or through contact with water. While all patients experienced pain and functional limitation, the social effects of arthritis were gender-specific: women noted interference with homemaking and churchgoing activities, while men experienced disruption with occupational roles. The coping strategies used by patients appeared to reflect their beliefs about disease causation and included prayer and avoidance of water. CONCLUSIONS: Patients' explanatory models of arthritis influenced the psychosocial effects of the disease and coping mechanisms used. Given the increasing reach of global health programs, understanding these culturally influenced perceptions of disease will be crucial in successfully treating chronic diseases in the developing world.

Short-Term Surgical Missions: Role of Pharmacist Volunteers.

Health care professionals often participate in short-term surgical missions in underserved areas of the world. Surgical missions often rely on the use of medications to provide health care to these underserved areas in patients with multiple comorbid conditions. The direct role a pharmacist may have in surgical missions is not well described in the literature; however, numerous opportunities exist for pharmacist involvement to improve patient care and operational processes throughout medication planning and delivery of surgical missions. Pharmacists have specialized knowledge in medication acquisition, preparation, and distribution that result in a unique position to contribute positively to the mission's clinical and operational dynamics. Pharmacists may assist in various activities such as medication ordering, accrual, purchasing and preparing during the surgical mission. Pharmacists may also provide clinical support and offer alternative medications in the setting of drug intolerance or allergies. In 2008, Operation Walk Boston, a short-term surgical mission was established to provide hip and knee joint replacements to patients in the Dominican Republic. Pharmacists and pharmacy residents play a crucial role as members of this surgical mission. Based on our experience, this article aims to describe the evolving role of pharmacists as a member of a surgical mission.

Factors associated with use of antibiotic prophylaxis following dental procedures in total joint replacement recipients.

Background: Total joint replacement recipients (TJR) are at risk for prosthetic joint infection (PJI), particularly those with comorbidities such as diabetes mellitus (DM) and rheumatoid arthritis (RA). Methods: We mailed surveys to 1078 subjects undergoing primary TJR between 2011 and 2016 â€‹at an academic center. The survey asked about medical, dental, and orthopedic history and use of antibiotics prior to dental appointments. We generated adjusted relative risks (aRR) for using antibiotic prophylaxis less than always using Poisson regression, adjusting for demographic, clinical, and behavioral factors. Results: We received surveys from 639 subjects; 597 were eligible and formed the analytical sample. 66 â€‹% reported always using antibiotic prophylaxis. DM and RA were not associated with prophylaxis use. Factors associated with less frequent use included: BMI ≥30 (aRR â€‹= â€‹1.27, 95 â€‹% CI [1.01, 1.60]), dental cleanings <2 times/year (aRR â€‹= â€‹1.95, 95 â€‹% CI [1.56, 2.43]), and expressing little concern (compared to neutral) about getting PJI (aRR â€‹= â€‹1.23, 95 â€‹% CI [0.97, 1.55]), though this association was not statistically significant. Greater antibiotic use was reported in subjects who had ≥3 TJRs, (aRR â€‹= â€‹0.48, 95 â€‹% CI [0.29, 0.80]), underwent more invasive dental procedures (aRR â€‹= â€‹0.74, 95 â€‹% CI [0.59, 0.93]), and were concerned (vs. neutral) about PJI (aRR â€‹= â€‹0.53, 95 â€‹%CI [0.33, 0.84]). Conclusions: Two-thirds of TJR recipients in an academic center reported always using antibiotic prophylaxis prior to dental visits. Usage rates varied by demographics, BMI, number of TJRs, type of dental procedure, and behavioral factors -- but not by comorbidities associated with higher PJI risk.

Discordance in femoral neck bone density in subjects with unilateral hip osteoarthritis.

Osteoarthritis (OA) is a common disease that increases in incidence with age and currently affects an estimated 27 million Americans. To determine whether site-specific hip bone mineral density (BMD) measures are confounded by the presence of OA, we measured bilateral hip BMD by dual X-ray absorptiometry in 34 subjects (19 women and 15 men) scheduled for hip replacement for confirmed advanced unilateral hip OA. The femoral neck (FN) BMD (p=0.035) and T-score (p=0.017) for the hip with OA was higher than those of the contralateral hip. There was a difference in osteoporosis classification depending on which hip was considered: for 11 of the 34 subjects (32%), the FN T-score was normal for OA hip, but the contralateral hip was classified as osteopenic (T-score between -1.0 and -2.5). For 1 subject, the FN T-score was normal for OA hip, but the contralateral hip was classified as osteoporotic (T-score below -2.5). Discordance was also present for trochanter values and not for total hip values. These data indicate that advanced hip OA can be associated with a higher bone density at the FN and trochanter but not at total hip and that the discrepancy between hips at the FN may have an impact on patient treatment decisions.

Cost-effectiveness of dental antibiotic prophylaxis in total knee arthroplasty recipients with type II diabetes mellitus.

Objective: Type II diabetes mellitus (T2DM) is prevalent in knee osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA) and increases risk for prosthetic joint infection (PJI). We examined the cost-effectiveness of antibiotic prophylaxis (AP) before dental procedures to reduce PJI in TKA recipients with T2DM. Design: We used the Osteoarthritis Policy Model, a validated computer simulation of knee OA, to compare two strategies among TKA recipients with T2DM (mean age 68 years, mean BMI 35.4 kg/m2): 1) AP before dental procedures and 2) no AP. Outcomes included quality-adjusted life expectancy (QALE) and lifetime medical costs. We used published efficacy of AP. We report incremental cost-effectiveness ratios (ICERs) and considered strategies with ICERs below well-accepted willingness-to-pay (WTP) thresholds cost-effective. We conducted sensitivity analyses to examine the robustness of findings to uncertainty in model input parameters. We used a lifetime horizon and healthcare sector perspective. Results: We found that AP added 1.0 quality-adjusted life-year (QALY) and $66,000 for every 1000 TKA recipients with T2DM, resulting in an ICER of $66,000/QALY. In sensitivity analyses, reduction of the probability of PJI, T2DM-associated risk of infection, or attribution of infections to dental procedures by 50% resulted in ICERs exceeding $100,000/QALY. Probabilistic sensitivity analyses showed that AP was cost-effective in 32% and 58% of scenarios at WTP of $50,000/QALY and $100,000/QALY, respectively. Conclusions: AP prior to dental procedures is cost-effective for TKA recipients with T2DM. However, the cost-effectiveness of AP depends on the risk of PJI and efficacy of AP in this population.

Basics of primary total hip arthroplasty: preoperative and postoperative decisions.

Preoperative planning, choice of implant-bearing surface materials to reduce wear, factors to minimize the incidence of postoperative dislocation, and the critical postoperative care issues to facilitate a rapid recovery are important considerations in patients undergoing total hip arthroplasty.