Increased Risk of Periprosthetic Joint Infections in Patients With Hypothyroidism Undergoing Total Joint Arthroplasty

Elevated risk of medical and implant-related complications in patients with hypothyroidism after total shoulder arthroplasty: a 1:1 propensity matched cohort analysis

BACKGROUND

There is currently limited work that evaluates the effect of comorbid hypothyroidism on complications and outcomes following total shoulder arthroplasty (TSA). This study aims to evaluate the impact of hypothyroidism on 90-day medical complications as well as 2-year implant related complications and revision rates following TSA.

METHODS

This retrospective database analysis evaluated patients who underwent TSA between October 1, 2015, and March 9, 2022. Patients with 2-year follow-up were categorized based on the presence of preoperative hypothyroidism within three months before TSA versus euthyroid status, resulting in 7716 hypothyroid and 46,568 euthyroid patients. A 1:1 propensity score matching was performed, adjusting for age, gender, race, ethnicity, and comorbid conditions (diabetes, hypertension, chronic kidney disease, tobacco use, obesity, heart failure, and liver diseases). Postoperative complications were assessed at 90 days, and implant-related complications were evaluated at two years. A Bonferroni correction was applied to account for multiple comparisons.

RESULTS

After matching, 7716 matched patients were included in each cohort. Hypothyroid patients had significantly higher risks of sepsis, infection, pulmonary embolism, stroke, and hospital readmission (all P < .0001), as well as higher rates of anemia, pneumonia, renal failure, and blood transfusion requirements (all P < .0001) within 90 days postoperatively. Myocardial infarction did not meet the significance threshold (P = .005). At 2 years, these patients had elevated rates of periprosthetic fractures, prosthetic joint infection, dislocation, revision surgeries, and mechanical loosening (all P < .0001).

CONCLUSION

Hypothyroidism is associated with an increased risk of 90-day medical complications and 2-year implant-related complications following shoulder arthroplasty. Further investigation into these findings and potential for perioperative medical optimization is indicated.

Is the Presence of Sinus Tract in Periprosthetic Joint Infection Still One of the Main Deciding Factors for Septic Revision?

Introduction Two of the most common complications of joint arthroplasty surgery are aseptic and septic loosening. While aseptic loosening has a well-established treatment protocol, and diagnosis is quite straightforward, bacterial colonization of the implants is associated with a more difficult diagnosis and treatment, more surgeries, and higher morbidity for the patient. Accurate diagnosis is essential in choosing the right treatment plan. The aim of the current study was to assess the current diagnostic methods for periprosthetic joint infection and the influence of clinical signs like sinus tract on the treatment algorithm and outcomes of the patients. We wanted to highlight that sinus tract is still one of the major criteria in periprosthetic joint infection diagnosis and its presence increases the probability of choosing the right therapeutic option. Materials and methods During the three-year period of the study, we included 48 cases of patients who presented in our hospital with pain around their hip or knee prostheses. Inclusion criteria were patients diagnosed with septic or aseptic loosening of the prosthesis that required surgical revision of the implant in one stage or two stages. We excluded patients who did not require surgery yet or had major contraindications for revision surgery, patients who refused surgery, acute periprosthetic joint infections (less than 1 month since implantation), or extrinsic mechanical complications of the prosthesis like periprosthetic fractures, implant dislocations. Results Out of 48 patients, 25 underwent one-stage revision and 23 underwent two-stage revision surgery (septic revision). In the subgroup of two-stage revision, 18 patients (78.2%) presented a sinus tract communicating with the prosthesis, this clinical sign being a major characteristic of the subgroup. We managed to successfully identify 21 out of 23 cases (91.3%) of periprosthetic joint infections prior to or during the surgery. In the two cases in which we misdiagnosed the infection, the sinus tract or a positive bacterial culture was absent prior to surgery, in addition to other clinical or paraclinical findings indicating only a small probability of periprosthetic joint infection, influenced the attending medical doctor's therapeutic decision. In these particular cases of culture-negative periprosthetic joint infections, the outcome was poor, with patients needing additional surgeries in order to eradicate the infection. Discussion When present, a clear sign of periprosthetic joint infection, such as a sinus tract, facilitates the diagnostic protocol and allows the medical staff to initiate the appropriate treatment earlier. In the absence of such obvious signs, differential diagnosis remains difficult, and we should consider the future development of faster, cheaper, and more accurate tests for periprosthetic joint infection diagnosis, especially for chronic low-grade infections that could be easily misdiagnosed.

Hypothyroidism Impacts Clinical and Healthcare Utilization Outcomes After Primary Total Hip Arthroplasty

BACKGROUND

Our objective was to assess the association of hypothyroidism with outcomes of primary total hip arthroplasty (THA) overall and stratified by underlying diagnosis.

METHODS

We identified patients undergoing primary THA in a national database from 2016 to 2020. We stratified them based on primary diagnoses into hip osteoarthritis (OA; N = 1,761,960), osteonecrosis (ON; N = 78,275), traumatic fracture (N = 532,910), inflammatory arthritis (IA; N = 3,520), and "other" (N = 90,550). We identified hypothyroidism and complications using secondary diagnoses. Among 2,467,215 patients undergoing primary THA, mean age was 68 years (range, 18 to 90), and 58.3% were women. Complications codes only included initial encounters. We performed time-trends analyses and multivariable-adjusted regression analyses adjusted for demographics, expected primary payer, a comorbidity score, elective versus non-elective admission, and hospital characteristic information, with clinical and healthcare utilization outcome as endpoints.

RESULTS

Overall, hypothyroidism was significantly associated with increased LOS, total charges, non-routine discharges, blood transfusions, and prosthetic fractures. In the OA cohort, hypothyroidism was associated with increased LOS, total charges, and non-routine discharges (P < .001 for each), and blood transfusions (P = .02). Hypothyroidism was associated with increased total charges (P = .001) in the ON cohort and with increased LOS, non-routine discharge, and blood transfusion (P < .05 each) in the traumatic fracture cohort.

CONCLUSIONS

Hypothyroidism was associated with blood transfusions, prosthetic fractures, and utilization outcomes in THA patients. Tailored intervention strategies for hypothyroidism should be tested for their efficacy to improve THA peri-operative outcomes.

Neuroimmune modulation in liver pathophysiology

The liver, the largest organ in the human body, plays a multifaceted role in digestion, coagulation, synthesis, metabolism, detoxification, and immune defense. Changes in liver function often coincide with disruptions in both the central and peripheral nervous systems. The intricate interplay between the nervous and immune systems is vital for maintaining tissue balance and combating diseases. Signaling molecules and pathways, including cytokines, inflammatory mediators, neuropeptides, neurotransmitters, chemoreceptors, and neural pathways, facilitate this complex communication. They establish feedback loops among diverse immune cell populations and the central, peripheral, sympathetic, parasympathetic, and enteric nervous systems within the liver. In this concise review, we provide an overview of the structural and compositional aspects of the hepatic neural and immune systems. We further explore the molecular mechanisms and pathways that govern neuroimmune communication, highlighting their significance in liver pathology. Finally, we summarize the current clinical implications of therapeutic approaches targeting neuroimmune interactions and present prospects for future research in this area.

Impact of diabetic kidney disease on post-operative complications after primary elective total hip arthroplasty: a nationwide database analysis

BACKGROUND

The high prevalence of diabetic kidney disease (DKD) in the United States necessitates further investigation into its impact on complications associated with total hip arthroplasty (THA). This study utilizes a large nationwide database to explore risk factors in DKD cases undergoing THA.

METHODS

This research utilized a case-control design, leveraging data from the national inpatient sample for the years 2016 to 2019. Employing propensity score matching (PSM), patients diagnosed with DKD were paired on a 1:1 basis with individuals free of DKD, ensuring equivalent age, sex, race, Elixhauser Comorbidity Index (ECI), and insurance coverage. Subsequently, comparisons were drawn between these PSM-matched cohorts, examining their characteristics and the incidence of post-THA complications. Multivariate logistic regression analysis was then employed to evaluate the risk of early complications after surgery.

RESULTS

DKD's prevalence in the THA cohort was 2.38%. A 7-year age gap separated DKD and non-DKD patients (74 vs. 67 years, P < 0.0001). Additionally, individuals aged above 75 exhibited a substantial 22.58% increase in DKD risk (49.16% vs. 26.58%, P < 0.0001). Notably, linear regression analysis yielded a significant association between DKD and postoperative acute kidney injury (AKI), with DKD patients demonstrating 2.274-fold greater odds of AKI in contrast with non-DKD individuals (95% CI: 2.091-2.473).

CONCLUSIONS

This study demonstrates that DKD is a significant risk factor for AKI in patients undergoing total hip arthroplasty. Optimizing preoperative kidney function through appropriate interventions might decrease the risk of poor prognosis in this population. More prospective research is warranted to investigate the potential of targeted kidney function improvement strategies in reducing AKI rates after THA. The findings of this study hold promise for enhancing preoperative counseling by surgeons, enabling them to provide DKD patients undergoing THA with more precise information regarding the risks associated with their condition.

Association of preoperative thyroid hormone replacement with perioperative complications after major abdominal surgery

OBJECTIVE

To determine the association between preoperative thyroid hormone replacement and complications following major abdominal surgery.

METHODS

A retrospective case series was performed of patients enrolled in the Michigan Surgical Quality Collaborative (MSQC) who underwent major abdominal surgery at an academic institution over a 10-year period. The principal explanatory variable was preoperative thyroid hormone replacement. Primary outcomes were morbidity, mortality and length of stay.

RESULTS

2700 patients were identified. On multivariate analysis correcting for established predictors of operative morbidity, patients on preoperative thyroid replacement had a 1.5- fold increased risk of serious morbidity(p ​= ​0.01), and a 1.7- fold greater risk for serious sepsis(p ​= ​0.04). Thyroid replacement was associated with longer length of stay(p ​< ​0.001). While there was a high degree of missing data for surgical approach (31.1 ​% missing data), results suggest that patients on thyroid hormone replacement were more likely to undergo an open rather than minimally invasive surgery(p ​< ​0.01). Open surgery was associated with greater risk of serious morbidity(p ​= ​0.003) and longer length of stay(p ​< ​0.001).

CONCLUSIONS

Preoperative thyroid hormone replacement independently predicts operative morbidity and length of stay following major abdominal surgery.

Preoperative Risk Factors for Periprosthetic Joint Infection: A Narrative Review of the Literature

Periprosthetic joint infection (PJI) poses a challenging complication for many patients undergoing arthroplasty, and the literature identifies numerous risk factors. A comprehensive understanding of the primary risk and protective factors for PJI is valuable for surgeons. This article aims to compile and summarize the key risk factors for PJI documented in the literature. Some risk factors are related to the nutritional status of patients, with obesity, weight loss, hypovitaminosis, and malnutrition being frequently reported. Pathologies affecting patients also contribute to PJI risk, including septic arthritis, hepatitis, diabetes, urinary tract infections, anemia, hypothyroidism, osteoporosis, and dental pathologies. Unhealthy habits, such as tobacco and drug abuse, are significant factors. Previous corticosteroid injections may also play a role in infection development. A few protective factors are also reported in the literature (use of statins, preoperative decolonization, and preadmission skin preparation). The identification of risk factors and the implementation of evidence-based preoperative protocols are essential steps in reducing the incidence of PJI.

Effect of Hypothyroidism on Complications in Patients Undergoing TKA in Indian Population

Background

The number of hypothyroidism patients undergoing total knee replacement (TKA) in India is increasing. It is assumed that patients with hypothyroidism are more prone to complications following surgery. The aim of this study is to evaluate the impact of hypothyroidism on the complications following TKA.

Methods

This is a case-control analysis of patients who underwent primary total knee replacement in our hospital from 2017 to 2019. A total of 600 patients were included in the study, of which 300 patients were with hypothyroidism. We compared with a matched cohort of another 300 patients without hypothyroidism as control group.

Results

A total of 600 patients were analyzed (Hypothyroid group n = 300, Control group n = 300). The medical complications were found to be 6.2% in the hypothyroid group compared to 4% in control group (p = 1.66, odds ratio 0.61). Surgical complications in the hypothyroid group were 3% compared to 0.6% in control group (p = 4.53, odds ratio = 0.21), overall complication rates were not significant statistically when compared between hypothyroid and control group (p = 5.01, odds ratio 0.47). Subgroup analysis of complications of hypothyroid patients with euthyroid status versus uncontrolled hypothyroidism was done and we found no statistical difference in complications.

Conclusion

The conclusion can be that the rate of hospital stay, surgical site infections and complications were higher in hypothyroid group when compared with control group though statistically not significant.

Impact of Preoperative Quality of Life and Related Factors on the Development of Surgical Site Infections Following Primary Total Joint Arthroplasty: A Prospective Case-Control Study with a Five-Year Follow-Up

Introduction

As surgical site infections (SSIs) after joint arthroplasty contribute to increased morbidity and mortality, they require further surgical intervention, prolonged hospitalisation, and antimicrobial treatment. The aim of our study is to examine the association between preoperative quality of life (QoL) and other predictive factors on the development of SSIs after primary arthroplasty.

Methods

This is a prospective study that enrolled 56 patients with hip and knee primary osteoarthritis who underwent joint replacement. Data were collected from January to March 2017, including patient demographic characteristics, comorbidities, laboratory results, and perioperative clinical data. The patients' QoL was evaluated preoperatively by applying the knee injury and osteoarthritis outcome score (KOOS) and the hip disability and osteoarthritis outcome score (HOOS) for total knee replacement (TKR) and total hip replacement (THR), respectively. A 5-year follow-up was conducted to assess the clinical status of the patients.

Results

66.1% of patients underwent TKR, with 4.9 ± 1.2 days of hospitalisation, 16% of them required autologous blood transfusion, while 33.9% of patients were treated with THR, with 5.7 ± 1 days hospitalisation and 36.8 of them required this type of transfusion. 16 patients were diagnosed with SSIs, with the older of them (>65 years old) presenting lower probability (odds ratio: 0.13, 95% CI: 0.03-0.62) requiring treatment with additional antibiotics, while revision surgery was performed in 3 of these cases, following periprosthetic joint infection (PJI). Overall preoperative QoL was not statistically associated with SSIs, but low QoL scores were associated with higher rates of SSIs and increased levels of postoperative pain (p = 0.009 < 0.05).

Conclusions

The duration of each operation (>90 min), the length of hospitalisation (>4 days), and the presence of comorbidities including hypothyroidism and recurrent urinary tract infections were associated with a high risk for SSIs following arthroplasties. On the contrary, this study revealed no association between other comorbidities, including heart coronary disease, hypertension, and diabetes mellitus, with close monitoring of plasma glucose and SSIs. Moreover, the younger the patients, the more likely they were to require treatment with antibiotics. Overall, high QoL index scores were mainly accompanied by low rates of postoperative SSIs and pain.

Risk factors for the development of a peri-prosthetic joint infection up to 2 Years following primary reverse shoulder arthroplasty

Background

Reverse shoulder arthroplasty (RSA) has become commonly used to treat glenohumeral osteoarthritis (GHOA), of which complications such as peri-prosthetic joint infections (PJIs) may develop. The objective of this study was to compare patient demographics of those who did and did not develop PJIs within 2 years after primary RSA for GHOA and identify risk factors for this sequela.

Methods

A nationwide database was queried from 2005 to 2014 for Medicare patients treated with primary RSA (International Classification of Disease (ICD-9) procedural code 81.88) for GHOA. Patients who developed PJIs within 2-years of primary RSA defined the study group, whereas those who were devoid of infections represented the comparison group. Our study consisted of 51,824 patients, of which 879 (1.69%) developed a PJI. Patient demographics comprising the Elixhauser comorbidity index (ECI) were compared using Chi-Square analyses. Multivariable logistic regression models were used to compute the odds-ratios (OR) of patient-specific factors associated with acquiring a PJI within 2 years after RSA. P values less than 0.002 were significant.

Results

Patients developing a PJI had higher mean ECI (8 vs. 6; p < 0.0001). The greatest risk factors for developing PJIs within 2-years following RSA were male sex (OR: 2.10, 95%CI: 1.81-2.43, p < 0.0001), pathologic weight loss (OR: 1.78, 95%CI: 1.45-2.17, p < 0.0001), iron deficiency anemia (OR: 1.75, 95%CI: 1.49-2.06, p < 0.0001), morbid obesity (OR: 1.52, 95%CI: 1.21-1.88, p = 0.0001), rheumatoid arthritis (OR: 1.32, 95%CI: 1.13-1.54, p = 0.0003), arrhythmias (OR: 1.26, 95%CI 1.09-1.46, p = 0.001), and depressive disorders (OR: 1.23, 95%CI 1.06-1.43, p = 0.001).

Conclusions

The greatest risk factors for PJIs within 2 years of primary RSA included male sex; additional modifiable risk factors included iron deficiency anemia, pathologic weight loss, and obesity. Preoperative screening can help to identify modifiable risk factors and alter management for high-risk patients to potentially minimize PJIs.

Hypothyroidism and Spine Surgery: a Review of Current Findings

PURPOSE OF REVIEW

Hypothyroidism is a common medical comorbidity and has been linked to adverse surgical outcomes. However, its effect on spine surgery outcomes is less clear. The aim of this review is to compile current literature to serve as a guide for spine surgeons when treating patients with hypothyroidism.

RECENT FINDINGS

In both the cervical and lumbar spine, patients with hypothyroidism are at increased risk of postoperative medical complications. Consequently, patients with hypothyroidism experience increased healthcare costs and readmission rates. However, there are some contradictory findings with some studies suggesting that hypothyroidism may have a protective effect in patients undergoing lumbar fusion, specifically against postoperative myocardial infraction and decreased inpatient mortality. When examining spine surgery outcomes, there are mixed results when considering the effect of hypothyroidism. Some studies have shown increased medical complications, hardware failure, and increased expenditure; however, other recent findings suggest possible protective effects. Future studies are needed to help create concrete guidelines for treating patients with hypothyroidism.

Intra-Articular Corticosteroid or Hyaluronic Acid Injections Are Not Associated with Periprosthetic Joint Infection Risk following Total Knee Arthroplasty

This study evaluated whether the preoperative use and timing of the use of hyaluronic acid (HA) and/or corticosteroid (CS) injections were associated with an increased risk of periprosthetic joint infections (PJIs) following primary total knee arthroplasty (TKA). We tested the hypothesis that preoperative injection of HA or CS within 3 months prior to primary TKA was associated with an increased risk of PJI by specifically evaluating the association between PJI risk and (1) injection type; (2) timing; (3) patient demographic factors; and (4) surgery-related factors, such as surgeon injection volume, knee arthroscopy (pre- and postoperative), and hospital length of stay. The 5% Medicare part B claims database was queried for patients who received CS and/or HA injections. Cox proportional hazards regressions evaluated the risk of PJIs after TKA, adjusting for patient and clinical factors, as well as propensity scores. The unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 0.89% for the HA group, 0.96% for both CS and HA group, and 0.75% for those who did not use HA or CS in the 12 months before TKA. For patients who used HA and/or CS within 3 months prior to TKA, the unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 1.07% for the HA group, and 1.00% for both CS and HA group, compared with 0.77% for those who did not use HA or CS. The number of injections performed per year was inconsistently associated with PJI risk. Overall, we found that intra-articular injections given within the 4-month period prior to TKA were not associated with elevated PJI risk (evaluated at 1, 3, 12, and 24 months after the index TKA) within the elderly Medicare patient population.

Thyroid function and risk of bloodstream infections: Results from the Norwegian prospective population-based HUNT Study

OBJECTIVE

Previous studies on thyroid function and risk of infection is conflicting and often stem from intensive care cohorts were nonthyroidal illness syndrome (NTIS) may be present. The objective of this study was to identify the risk of bloodstream infections (BSI) and BSI-related mortality with thyroid-stimulating hormone (TSH) levels within the reference range in a general population.

DESIGN

Prospective follow-up.

PARTICIPANTS

The HUNT2 (1995-97) included 34,619 participants with information on TSH levels.

MEASUREMENTS

Hazard ratios (HRs) with 95% confidence interval (CI) confirmed BSIs and BSI-related mortality until 2011.

RESULTS

During a median follow-up of 14.5 years, 1179 experienced at least one episode of BSI and 208 died within 30 days after a BSI. TSH levels within the reference range of 0.5-4.5 mU/L were not associated with the risk of first-time BSI, with an HR of 0.97 (95% CI: 0.90-1.04) per mU/L. Stratified by baseline age < or ≥65 years, TSH was inversely associated with the risk of BSI (HR: 0.88; 95% CI: 0.78-1.00 per mU/L) in the youngest age group only. Persons with any baseline thyroid disease had a 30% risk and the hyperthyroid subgroup a 57%, and hypothyroidism a 20% increased risk of BSI. TSH levels were not clearly associated with BSI mortality, but the HRs were imprecise due to few BSI-related deaths.

CONCLUSION

There was some evidence of a weak inverse association between TSH levels and the risk of BSI in persons below 65 years of age. The increased risk seen in persons with thyroid illness is probably explained by confounding by concurrent ill health.

Negative Association of Subclinical Hypothyroidism on Improvement in Patient-Reported Outcomes After Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to analyze the potential influence of subclinical hypothyroidism (SCH) on improvement in patient-reported outcome measures following primary total knee arthroplasty.

METHODS

A prospective, comparative cohort study between 92 SCH and 90 euthyroid patients was performed. Patients were followed up to 5 postoperative years. Patient-reported outcome measure was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. The Knee Society Scores were used for functional evaluation, and 5-point Likert scale for patient satisfaction. The Hospital Anxiety and Depression scale was also used.

RESULTS

All outcome scores significantly improved from preoperative to final follow-up in both groups (P = .001). There were no significant differences between groups in Knee Society Scores (P = .057) at the final follow-up, but Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly lower in the SCH group (P = .015). Likewise, the patient satisfaction rate was significant lower in the SCH group (0.010).

CONCLUSION

SCH patients have a slower functional recovery than euthyroid patients, and trended toward lower improvements in patient-reported scores. Depression was the most important negative factor. The findings of this study can provide the surgeon with an important information for better counseling the SCH patients.

The interplay of thyroid hormones and the immune system - where we stand and why we need to know about it

Over the past few years, growing evidence suggests direct crosstalk between thyroid hormones (THs) and the immune system. Components of the immune system were proposed to interfere with the central regulation of systemic TH levels. Conversely, THs regulate innate and adaptive immune responses as immune cells are direct target cells of THs. Accordingly, they express different components of local TH action, such as TH transporters or receptors, but our picture of the interplay between THs and the immune system is still incomplete. This review provides a critical overview of current knowledge regarding the interaction of THs and the immune system with the main focus on local TH action within major innate and adaptive immune cell subsets. Thereby, this review aims to highlight open issues which might help to infer the clinical relevance of THs in host defence in the context of different types of diseases such as infection, ischemic organ injury or cancer.

The Potential Mechanisms of High-Velocity, Low-Amplitude, Controlled Vertebral Thrusts on Neuroimmune Function: A Narrative Review

The current COVID-19 pandemic has necessitated the need to find healthcare solutions that boost or support immunity. There is some evidence that high-velocity, low-amplitude (HVLA) controlled vertebral thrusts have the potential to modulate immune mediators. However, the mechanisms of the link between HVLA controlled vertebral thrusts and neuroimmune function and the associated potential clinical implications are less clear. This review aims to elucidate the underlying mechanisms that can explain the HVLA controlled vertebral thrust--neuroimmune link and discuss what this link implies for clinical practice and future research needs. A search for relevant articles published up until April 2021 was undertaken. Twenty-three published papers were found that explored the impact of HVLA controlled vertebral thrusts on neuroimmune markers, of which eighteen found a significant effect. These basic science studies show that HVLA controlled vertebral thrust influence the levels of immune mediators in the body, including neuropeptides, inflammatory markers, and endocrine markers. This narravtive review discusses the most likely mechanisms for how HVLA controlled vertebral thrusts could impact these immune markers. The mechanisms are most likely due to the known changes in proprioceptive processing that occur within the central nervous system (CNS), in particular within the prefrontal cortex, following HVLA spinal thrusts. The prefrontal cortex is involved in the regulation of the autonomic nervous system, the hypothalamic-pituitary-adrenal axis and the immune system. Bi-directional neuro-immune interactions are affected by emotional or pain-related stress. Stress-induced sympathetic nervous system activity also alters vertebral motor control. Therefore, there are biologically plausible direct and indirect mechanisms that link HVLA controlled vertebral thrusts to the immune system, suggesting HVLA controlled vertebral thrusts have the potential to modulate immune function. However, it is not yet known whether HVLA controlled vertebral thrusts have a clinically relevant impact on immunity. Further research is needed to explore the clinical impact of HVLA controlled vertebral thrusts on immune function.

Musculoskeletal Manifestations in Sjogren's Syndrome: An Orthopedic Point of View

Sjogren's syndrome (SS) is a frequent entity with a broad symptomatology spectrum, mainly affecting the salivary and lachrymal glands. The disease also affects the musculoskeletal system targeting bones, specific joints, muscles, and the peripheral nerve system. Disease related clinical manifestations canhave an accumulative impact, as the syndrome is commonly associated with other rheumatic diseases. A literature review was performed with the aim to assess the in-depth association of Sjogren's syndrome and its treatment agents with the musculoskeletal system and further investigate its potential relevance with common orthopedic postoperative complications.

Subclinical Hypothyroidism Affects Postoperative Outcome of Patients Undergoing Total Knee Arthroplasty

OBJECTIVE

The aim of this study was to investigate whether subclinical hypothyroidism could increase the risk of postoperative complications in patients undergoing primary total knee arthroplasty (TKA).

METHODS

A prospective case-control study of 796 patients undergoing primary TKA between January 2015 and January 2020 was performed. A total of 700 patients (87.9%) were female and the average age of included patients was 65.0 years, with a standard deviation of 5.6. The participants who had subclinical hypothyroidism were referred to as the case group, while those without abnormal thyrotropin (TSH) were included in the control group (matched for age and gender). The fasting plasma levels of TSH were tested in the morning in all patients. The diagnosis of subclinical hypothyroidism was completed by a senior endocrinologist based on laboratory tests; namely, a serum TSH ≥ 5 mu/L and normal free thyroxine (FT4). Subclinical hypothyroidism was further described as mild (TSH < 10 mu/L) or severe (TSH ≥ 10 mu/L). The incidence of 90-day postoperative complications was compared between two cohorts. Logistic regression analysis was used for the risk factors of 90-day postoperative complications following TKA.

RESULTS

A total of 398 patients had a diagnosis of subclinical hypothyroidism. Among them, 275 cases (69.1%) were described as mild (79 patients [19.8%] with low FT4 and 196 patients [49.2%] with normal FT4 in the repeated test) and 123 cases (30.9%) as severe subclinical hypothyroidism. Of the 196 patients (49.2%) with mild subclinical hypothyroidism and normal FT4, 63 patients (15.8%) had symptoms before surgery. Patients were followed up for an average duration of 25.4 months (6 to 43 months). A total of 265 patients (66.6%) received preoperative treatment for subclinical hypothyroidism, with an average therapy time of 9.2 months. There were 162 patients (40.7%) with positive autoantibodies to thyroid peroxidase (anti-TPO). There were no statistically significant differences in baseline data between cohorts (all P > 0.05). As for the cumulative 90-day outcomes, subclinical hypothyroidism increased the incidences of both medical and surgical complications following primary TKA compared to those without this condition (11.6% vs 7.2%, OR = 1.55, 95% confidence interval [CI] = 1.47-1.62, P < 0.05). Subclinical hypothyroidism caused patients to suffer increased total incidence of readmission within the first 90 days after discharge when compared to those without this condition (20.61% vs 14.15%, OR = 1.45, 95% CI = 1.41-1.49, P < 0.001). Controlling for preoperative and intraoperative variables, the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation were more likely to experience postoperative complications within 90 days of TKA.

CONCLUSION

Subclinical hypothyroidism might increase the risk of postoperative complications within 90 days of TKA, especially for the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation.

[Prosthetic infections and the increasing importance of psychological comorbidities : An epidemiological analysis for Germany from 2009 through 2019]

Hintergrund

Die periprothetische Gelenkinfektion (PJI) ist eine gefürchtete Komplikation in der Orthopädie und Unfallchirurgie. Ein potenzieller Anstieg an PJI-Diagnosen, insbesondere in Verbindung mit psychologischen Komorbiditäten, kann zu einer besonderen Herausforderung für Akteure im Gesundheitswesen werden. Bisher ist die Prävalenz für Deutschland unbekannt. Dies erschwert es, den zukünftigen Behandlungsbedarf abzuschätzen und Entwicklungen vorherzusehen, die durch eine Anpassung von Präventions- und Therapiemaßnahmen beeinflusst werden können.

Ziel der Arbeit

Die vorliegende Arbeit gibt eine detaillierte Übersicht über die Epidemiologie periprothetischer Gelenkinfektionen und psychologischer Komorbiditäten.

Material und Methoden

Ein Datensatz vom Statistischen Bundesamt (Destatis) aus jährlichen, deutschlandweiten ICD-10-Diagnosekodes von 2009 bis 2019 wurde analysiert. Prävalenzraten des Kodes „T84.5 – Infektion und entzündliche Reaktion durch eine Gelenkendoprothese“ wurden nach Altersgruppe, Geschlecht und in Verbindung mit einer Nebendiagnose des Kapitels F quantifiziert und aufgeschlüsselt.

Ergebnisse

Seit 2009 steigen die PJI-Diagnosen kontinuierlich an, die Häufigkeit war im Jahr 2018 rückläufig. Im Jahr 2019 wurden 16.174 Fälle entsprechend einer Prävalenz von 23,8/100.000 Einwohner verzeichnet. Eine Entwicklung hinsichtlich mehr Diagnosen bei älteren Patienten wurde evident. Ein Viertel aller Patienten wiesen eine Nebendiagnosen im Bereich psychischer Störungen und Verhaltensstörungen auf, wobei sich die Anzahl an Patienten mit psychologischen Komorbiditäten im letzten Jahrzehnt verdoppelte.

Schlussfolgerung

Richtlinien zu Präventionsstrategien und psychologische Unterstützungsangebote sollten in der Unfallchirurgie implementiert werden.

Thyrotrophin and thyroxine support immune homeostasis in humans

The endocrine and the immune systems interact by sharing receptors for hormones and cytokines, cross‐control and feedback mechanisms. To date, no comprehensive study has assessed the impact of thyroid hormones on immune homeostasis. By studying immune phenotype (cell populations, antibody concentrations, circulating cytokines, adipokines and acute‐phase proteins, monocyte–platelet interactions and cytokine production capacity) in two large independent cohorts of healthy volunteers of Western European descent from the Human Functional Genomics Project (500FG and 300BCG cohorts), we identified a crucial role of the thyroid hormone thyroxin (T4) and thyroid‐stimulating hormone (TSH) on the homeostasis of lymphocyte populations. TSH concentrations were strongly associated with multiple populations of both effector and regulatory T cells, whereas B‐cell populations were significantly associated with free T4 (fT4). In contrast, fT4 and TSH had little impact on myeloid cell populations and cytokine production capacity. Mendelian randomization further supported the role of fT4 for lymphocyte homeostasis. Subsequently, using a genomics approach, we identified genetic variants that influence both fT4 and TSH concentrations and immune responses, and gene set enrichment pathway analysis showed enrichment of fT4‐affected gene expression in B‐cell function pathways, including the CD40 pathway, further supporting the importance of fT4 in the regulation of B‐cell function. In conclusion, we show that thyroid function controls the homeostasis of the lymphoid cell compartment. These findings improve our understanding of the immune responses and open the door for exploring and understanding the role of thyroid hormones in the lymphocyte function during disease.

Neuronal regulation of immunity: why, how and where?

Neuroimmunology is one of the fastest-growing fields in the life sciences, and for good reason; it fills the gap between two principal systems of the organism, the nervous system and the immune system. Although both systems affect each other through bidirectional interactions, we focus here on one direction - the effects of the nervous system on immunity. First, we ask why is it beneficial to allow the nervous system any control over immunity? We evaluate the potential benefits to the immune system that arise by taking advantage of some of the brain's unique features, such as its capacity to integrate and synchronize physiological functions, its predictive capacity and its speed of response. Second, we explore how the brain communicates with the peripheral immune system, with a focus on the endocrine, sympathetic, parasympathetic, sensory and meningeal lymphatic systems. Finally, we examine where in the brain this immune information is processed and regulated. We chart a partial map of brain regions that may be relevant for brain-immune system communication, our goal being to introduce a conceptual framework for formulating new hypotheses to study these interactions.

Possible role of hypothyroidism in the prognosis of COVID-19

In patients with COVID‐19, certain medical conditions could result in poorer clinical outcomes. However, the prognostic role of hypothyroidism in COVID‐19 is still unknown. In the present retrospective study, we estimated the prevalence of hypothyroidism in COVID‐19 admitted patients in Tehran, Iran. Among 390 COVID‐19 admitted patients, 21 hypothyroid cases (5.4%) were found, in which nearly 90% were aged 50 years and older. Regarding the effect of hypothyroidism on COVID‐19 mortality, 60 (15.3%) of total patients and 4 (19%) of hypothyroid patients died, and no significant difference was found between the two groups.

[Safety and effectiveness of total hip arthroplasty in patients with hypothyroidism]

Objective

To evaluate the safety and effectiveness of total hip arthroplasty (THA) in patients with hypothyroidism.

Methods

Sixty-three patients with hypothyroidism (hypothyroidism group) and 63 euthyroid patients without history of thyroid disease (control group) who underwent primary unilateral THA between November 2009 and November 2018 were enrolled in this retrospective case control study. There was no significant difference between the two groups in gender, age, body mass index, hip side, reason for THA, American Society of Anesthesiology (ASA) classification, preoperative hemoglobin (Hb) level, and preoperative Harris score ( P>0.05). The perioperative thyroid stimulating hormone (TSH) and thyroxine (T ₄) levels, the hypothyroidism-related and other complications during hospitalization, the decrease in Hb, perioperative total blood loss, blood transfusion rate, length of hospital stays, and 90 days readmissions rate in the two groups were recorded and evaluated. The periprosthetic joint infection, aseptic loosening of the prosthesis, and hip Harris score during follow-up were recorded.

Results

The differences in the TSH and T ₄ of hypothyroidism group between pre- and 3 days post-operation were significant ( P>0.05) and no hypothyroidism-related complications occurred after THA. The decrease in Hb and perioperative total blood loss in the hypothyroidism group were significantly higher than those in the control group ( P<0.05), but there was no significant difference between the two groups in terms of transfusion rate, length of hospital stays, and 90 days readmission rates ( P>0.05). No significant difference in the rate of complications (liver dysfunction, heart failure, pulmonary infection, urinary infection, and wound complication) between the two groups was found ( P>0.05) except for the rate of intramuscular vein thrombosis which was significantly lower in the hypothyroidism group, and the rate of postoperative anemia which was significantly higher in the hypothyroidism group ( P<0.05). The two groups were followed up 1.0-9.9 years (mean, 6.5 years). At last follow-up, Harris score in both groups were significantly higher than those before operation ( P<0.05). An increase of 39.5±12.3 in hypothyroidism group and 41.3±9.3 in control group were recorded, but no significant difference was found between the two groups ( t=0.958, P=0.340). During the follow-up, 1 case of periprosthetic joint infection occurred in the hypothyroidism group, no loosening or revision was found in the control group.

Conclusion

With the serum TSH controlled within 0.5-3.0 mU/L and T ₄ at normal level preoperatively, as well as the application of multiple blood management, hypothyroid patients can safely go through THA perioperative period and effectively improve joint function, quality of life, and obtain good mid-term effectiveness.

Does well-controlled overt hypothyroidism increase the risk of total knee arthroplasty?

BACKGROUND

Overt hypothyroidism is widely accepted as a risk factor for adverse events following total knee arthroplasty (TKA). However, no prior study has preoperatively reversed hypothyroidism and reevaluated its risk. This retrospective study aimed at investigating whether well-controlled overt hypothyroidism would still increase the risk of TKA.

METHODS

Between November 2009 and November 2016, patients diagnosed with overt hypothyroidism but well controlled and underwent TKA were compared with euthyroid TKA patients. Data were extracted from our departmental database. Chi-squared test and t-tests were used for comparisons.

RESULTS

Hypothyroid patients had more blood loss and lower postoperative haemoglobin (Hb) and haematocrit level than the control group (all P < 0.05). Although the postoperative anaemia rate was lower in the control group (P = 0.01), there was no significant difference in the transfusion rate between the two groups (2.99% versus 7.46%, P = 0.10) or in the rates of other complications (P > 0.05). Interestingly, intramuscular venous thrombosis rate in hypothyroid patients was significantly lower than that in the control group (1.49% versus 9.70%, P = 0.00). Clinical outcome scores were comparable between the two groups throughout the course. And only one case of infection occurred in the hypothyroid patients.

CONCLUSION

Well-controlled overt hypothyroidism did not increase the risk of TKA, except for perioperative blood loss. Surgeons should be aware that even if hypothyroidism is reversed, the risk of more perioperative blood loss still exists and that, consequently, perioperative blood management is still essential in this population.

Sex- and Gender-specific Analysis in Orthopaedic Studies

BACKGROUND

Orthopaedic studies have reported the prevalence of injuries and outcomes after treatment in men and women patients, and although these differences have been recognized, few studies have evaluated for gender-specific injury patterns, disease progression, and treatment outcomes. A thorough understanding of gender-related differences is important to better individualize treatment and improve outcomes.

QUESTIONS/PURPOSES

In this study, we sought (1) to determine the proportion of studies published in six orthopaedic journals that provided sex- or gender-specific analyses in 2016 and whether a difference was found in outcomes between men and women and (2) to evaluate whether this proportion varied across several orthopaedic subspecialty journals or between general orthopaedic journals and subspecialty journals.

METHODS

Six leading orthopaedic surgery journals were selected for review, including two general orthopaedic journals (Journal of Bone and Joint Surgery and Clinical Orthopaedics and Related Research®) and four subspecialty journals (American Journal of Sports Medicine, Journal of Arthroplasty, Journal of Shoulder and Elbow Surgery, and Spine). Journal issues published in the even-numbered months of 2016 were reviewed for clinical randomized controlled, cohort, and case-control studies in which women were a part of the study population. A total of 712 studies evaluating 24,607,597 patients met the criteria and were included in our review of publications from 2016. The selected studies were stratified based on whether gender was a variable in a multifactorial statistical model. Outcomes of interest included the proportion of patients who were women and the presence or absence of a gender-specific analysis. These endpoints were compared between journals.

RESULTS

Overall, 55% (13,565,773 of 24,607,597) of patients analyzed in these studies were women. Only 34% (241 of 712) of the studies published in 2016 included gender as variable in a multifactorial statistical model. Of these, 39% (93 of 241) demonstrated a difference in the outcomes between patients who were men and women. The Journal of Arthroplasty had the greatest percentage of patients who were women (60%, 9,251,068 of 15,557,187) and the American Journal of Sports Medicine had the lowest (44%, 1,027,857 of 2,357,139; p < 0.001). Orthopaedic subspecialty journals tended to include a greater percentage of women (54%) than did general orthopaedic journals (50%; p = 0.04).

CONCLUSION

Currently, it is unclear what percentage of published orthopaedic studies should include a gender-specific analysis. In the current study, more than one-third of publications that performed a gender-specific analysis demonstrated a difference in outcomes between men and women, thereby emphasizing the need to determine when such an analysis is warranted.

CLINICAL RELEVANCE

Future studies should aim to determine when a gender-specific analysis is necessary to improve the management of orthopaedic injuries in men and women. It is important for investigators at the individual-study level to look for every opportunity to ensure that both men's and women's health needs are met by performing appropriate by-sex and by-gender analyses, but not to perform them when they are unnecessary or inappropriate.

Identifying Risk Factors Associated With Postoperative Infection Following Elective Lower-Extremity Total Joint Arthroplasty

This article addresses the importance of identifying risk factors associated with postoperative infection following elective lower-extremity total joint arthroplasty. Specifically, this review discusses risk factors recognized by the American Academy of Orthopaedic Surgeons that should be carefully considered and assessed by the orthopaedic team in collaboration with the primary care provider before proceeding with surgery.

Thyroid-stimulating hormone (TSH) is associated with 30-day mortality in hip fracture patients

PURPOSE

The aim of this study is to assess the possible association between thyroid-stimulating hormone (TSH) and mortality in hip fracture patients.

PATIENTS AND METHODS

The study is based on a hip fracture database from Bispebjerg University Hospital (Copenhagen, Denmark). This database includes all hip fracture patients (ICD-10 codes DS720 (femoral neck), DS721 (pertrochanteric), and DS722 (subtrochanteric)) admitted to Bispebjerg Hospital from 1996 to 2012. From this database, we identified all surgically treated hip fracture patients aged > 60 years with available plasma TSH-measurements at admission.

RESULTS

Of the 914 included patients (24% men and 76% women), 10.5% died within 30 days. At inclusion, 161 (17.6%) of the patients were hyperthyroid (TSH < 0.65 mIU/L), 58 (6.4%) were hypothyroid (TSH > 4.8 mIU/L), while 695 (76.0%) were euthyroid (0.65 < TSH < 4.80 mIU/L), p = 0.03. Mortality was significantly higher in the two higher quartiles of TSH [Q3 (13.0%) and Q4 (15.4%)] compared to the two lower quartiles [Q1 (7.4%) and Q2 (6.2%), p = 0.0003. After adjustment for age, sex and Charlson Comorbidity Index (CCI) in a Cox proportional hazard model, the risk of 30-day mortality continued to be increased in patients with TSH above the median as compared to patients with TSH below the median (HR 2.1 (1.4-3.3), p = 0.0006].

CONCLUSION

The study demonstrates increased 30-day mortality in surgically treated hip fracture patients with plasma TSH levels above the median (1.41 mIU/L) at admission, even after adjusting for age, sex and CCI.

The Presence of Sinus Tract Adversely Affects the Outcome of Treatment of Periprosthetic Joint Infections

BACKGROUND

A sinus tract may be encountered in patients with periprosthetic joint infection (PJI) and constitutes a major criterion for diagnosis. The aim of this study is to identify associated factors for the presence of sinus tract and outcome of 2-stage exchange arthroplasty in these patients.

METHODS

We retrospectively reviewed all patients with PJI following hip and knee arthroplasty from 2000 to 2017. Of them, 161 patients with a sinus tract had a minimum follow-up of 1 year following 2-stage exchange arthroplasty. These patients were matched 1:2 with those without sinus tract by using propensity score matching. Treatment success was assessed using the modified Delphi criteria. A multiple logistic regression analysis was performed to determine the effect of sinus tract on the outcome and associated factors for the presence of sinus tract.

RESULTS

Factors significantly associated with sinus tract included smoking (odds ratio [OR] = 1.83), hypothyroidism (OR = 1.62), hypoalbuminemia (OR = 1.52), hip joint involvement (OR = 1.43), and prior revision surgery (OR = 1.37). Patients with sinus tract had a significantly higher rate of failure compared to those without sinus tract (OR = 2.94).

CONCLUSION

This study demonstrates that the presence of sinus tract in patients with PJI adversely affects the outcome of treatment of these patients. The presence of sinus tract may be a proxy for other issues such as poor periarticular soft tissue, the poor nutritional status of the host, and multiple prior operations. These findings need to be borne in mind when treating patients with PJI and a concomitant sinus tract.

Impact of Co-Morbidities on the Cost of Care in Primary Elective Joint Arthroplasty

BACKGROUND

The Comprehensive Care for Joint Replacement model is the newest iteration of the bundled payment methodology introduced by the Centers for Medicare and Medicaid Services. Comprehensive Care for Joint Replacement model, while incentivizing providers to deliver care at a lower cost, does not incorporate any patient-level risk stratification. Our study evaluated the impact of specific medical co-morbidities on the cost of care in total joint arthroplasty (TJA) patients.

METHODS

A retrospective study was conducted on 1258 Medicare patients who underwent primary elective TJA between January 2015 and July 2016 at a single institution. There were 488 males, 552 hips, and the mean age was 71 years. Cost data were obtained from the Centers for Medicare and Medicaid Services. Co-morbidity information was obtained from a manual review of patient records. Fourteen co-morbidities were included in our final multiple linear regression models.

RESULTS

The regression models significantly predicted cost variation (P < .001). For index hospital costs, a history of cardiac arrhythmias (P < .001), valvular heart disease (P = .014), and anemia (P = .020) significantly increased costs. For post-acute care costs, a history of neurological conditions like Parkinson's disease or seizures (P < .001), malignancy (P = .001), hypertension (P = .012), depression (P = .014), and hypothyroidism (P = .044) were associated with increases in cost. Similarly, for total episode cost, a history of neurological conditions (P < .001), hypertension (P = .012), malignancy (P = .023), and diabetes (P = .029) were predictors for increased costs.

CONCLUSION

The cost of care in primary elective TJA increases with greater patient co-morbidity. Our data provide insight into the relative impact of specific medical conditions on cost of care and may be used in risk stratification in future reimbursement methodologies.

Risk factors associated with periprosthetic joint infection after total elbow arthroplasty

BACKGROUND

For patients undergoing total elbow arthroplasty (TEA), the present study aimed to investigate: (i) what risk factors are associated with periprosthetic elbow infection; (ii) what is the incidence of infection after TEA; and (iii) what is the acuity with which these infections present?

METHODS

The Statewide Planning and Research Cooperative System database was used to identify all patients who underwent TEA between 2003 and 2012 in New York State. Admissions for prosthetic joint infection (PJI) were identified using ICD-9 (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnosis code 996.66. Multivariate analysis was used to determine risk factors that were independently prognostic for PJI.

RESULTS

Significant risk factors for PJI included hypothyroidism [odds ratio (OR) = 2.04; p = 0.045], tobacco use disorder (OR = 3.39; p = 0.003) and rheumatoid arthritis (OR = 3.31; p < 0.001). Among the 1452 patients in the study period who underwent TEA, 3.7% (n = 54) were admitted postoperatively for PJI. There were 30 (56%) early infections, 17 (31%) delayed infections and seven (13%) late infections.

CONCLUSIONS

Pre-operative optimization of thyroid function, smoking cessation and management of rheumatoid disease may be considered in surgical candidates for TEA. The results of the present study add prognostic data to the literature that may be helpful with patient selection and risk profile analysis.

LEVEL OF EVIDENCE

Level III: prognostic study.

Clinical Characteristics and Long-term Outcomes After Septic Arthritis of the Native Glenohumeral Joint: A 20-Year Retrospective Review

Septic arthritis of the native glenohumeral joint is rare, and there is little information available regarding the natural progression and long-term joint outcomes of this pathology. The authors performed a retrospective analysis of 97 patients with culture-positive glenohumeral septic arthritis between 1995 and 2015 at their institution with a mean clinical follow-up of 83.1 months. Patient records were reviewed to document demographic and laboratory data, clinical presentation, postoperative complications, recurrences, and subsequent shoulder arthroplasty. Common comorbidities uncovered included 20 immunocompromised patients (20.6%), intravenous drug use among 27 patients (27.8%), diabetes mellitus among 40 patients (41.2%), and 18 patients (18.5%) receiving hemodialysis. Staphylococcus aureus was the most common pathogen identified (61 patients; 62.8%), followed by streptococcal species (17 patients; 17.2%). Hematogenous spread of infection was the most common etiology of shoulder sepsis (40.2%). Seven patients (7.2%) developed shoulder sepsis of undetermined etiology in the absence of established risk factors, and 16 patients (16.4%) developed recurrent glenohumeral septic arthritis at a mean of 40 months following initial eradication of infection. Three patients (3.0%) eventually underwent same-side shoulder arthroplasty at a mean of 18 months following septic arthritis, with none experiencing a periprosthetic joint infection. Glenohumeral septic arthritis is highly unlikely in the absence of medical risk factors. Long-term recurrence after clinically successful treatment is low (16.5%), and few patients undergo elective arthroplasty following shoulder septic arthritis. However, orthopedic surgeons can expect 30% to 40% of patients to require multiple trips to the operating room to successfully treat the initial joint infection, regardless of treatment method. [Orthopedics. 2019; 42(1):e118-e123.].

Hypothyroidism increases 90-day postoperative complications in patients undergoing primary single level anterior cervical disectomy and fusion: a matched control analysis

Background

Anterior cervical discectomy and fusion (ACDF) is indicated for patients suffering from cervical radiculopathy, myelopathy, and degenerative disc disease, among other diseases. There is paucity in the literature regarding postoperative complications in patients undergoing primary ACDF with a diagnosis of hypothyroidism. The purpose of this study is to compare 90-day postoperative complications in patients with and without hypothyroidism undergoing primary ACDF.

Methods

A retrospective analysis was completed using a national administrative database known as Pearl Diver (Pearl Diver Technologies, Fort Wayne, Indiana) using the International Classification of Disease, ninth revision (ICD-9) codes. The study group consisted of patients having undergone ACDF with an active diagnosis of hypothyroidism 90 days prior to and on the day of surgery. Patients undergoing primary ACDF without hypothyroidism served as the control group. Patients in both groups were randomly matched according to age, gender, and Charlson-Comorbidity Index (CCI). The 90-day postoperative medical complications were assessed along with readmission rates and total cost of care.

Results

There were a total of 107,066 patients equally divided between the 2 cohorts. Patients with hypothyroidism had greater odds of developing complications such as non-healing surgical wound (OR: 2.27; P<0.001), pulmonary embolus (OR: 2.16; P<0.001), myocardial infarction (OR: 2.10; P<0.001), compared to patients in the control group after undergoing primary ACDF. Readmission rates were also higher in patients with hypothyroidism (OR: 1.45; P<0.001). Total cost of care was also greater in patients with hypothyroidism compared to patients without hypothyroidism undergoing primary ACDF.

Conclusions

Hypothyroidism is a risk factor for worse postoperative outcomes in patients undergoing primary ACDF. Appropriate preoperative optimization with thyroid hormone supplementation could potentially minimize the incidence of developing numerous medical complications, in addition to potentially lowering readmission rates and the total cost of care.

Interaction of obesity with smoking and inflammatory arthropathies increases the risk of periprosthetic joint infection: a propensity score matched study in a Chinese Han population

BACKGROUND

Although a large number of studies have identified obesity as an independent risk factor for the development of periprosthetic joint infection (PJI), the synergistic impacts of obesity with other factors on PJI remain unknown. Additionally, few studies have specifically explored the risk factors of PJI within a Chinese population.

AIMS

To investigate the association between obesity and PJI in a Chinese population, and identify synergistic impacts of obesity with other risk factors on the development of PJI.

METHODS

Three hundred and seven patients at a single institution with a diagnosis of PJI following primary total hip or knee arthroplasty, treated from 2008 to 2015, were identified. Each case was matched with two controls who did not develop PJI after primary total hip or knee arthroplasty in the study period using propensity score matching for several important parameters. Multi-variable logistic regression models were used to estimate the association between body mass index (BMI) and the risk of developing PJI. Interaction and stratified analyses were conducted according to age, sex, type of surgery, smoking status, alcohol use, diabetes, inflammatory arthritis, liver disease and renal disease.

FINDINGS

The multiple logistic analyses showed that obesity was associated with increased risk of PJI [odds ratio (OR) 2.48; 95% confidence interval (CI) 1.66-3.69]. When analysed as a continuous variable, BMI was also associated with increased risk of PJI (OR per 1 kg/m² increase in BMI 1.08; 95% CI 1.02-1.14). In the interaction analysis, patients who were obese and smoked had a higher OR of developing PJI than non-smokers who were obese (OR 3.54 vs 1.55, P-value for interaction=0.031). Similarly, the OR was much higher for patients with both obesity and inflammatory arthritis than for patients who were obese with no history of inflammatory arthritis (OR 3.9 vs 1.55, P-value for interaction=0.029). No other significant interactions were found in the association between obesity and PJI.

CONCLUSION

Obesity is an independent risk factor for the development of PJI in the Chinese Han population. Surgeons should be aware that obese patients who smoke or have inflammatory arthritis are at additional increased risk of PJI.

Hypothyroidism Increases 90-Day Complications and Costs Following Primary Total Knee Arthroplasty

BACKGROUND

Thyroid disease is common and often remains undetected in the US population. Thyroid hormone has an array of metabolic, immunologic, and musculoskeletal functions crucial to well-being. The influence of thyroid disease on perioperative outcomes following primary total knee arthroplasty (TKA) is poorly understood. We hypothesized that hypothyroidism was associated with a higher risk of postoperative complications and 90-day costs following primary TKA.

METHODS

The Medicare standard analytical files were queried using International Classification of Disease codes between 2005 and 2014 to identify patients undergoing primary TKA. Patients with a diagnosis of hypothyroidism were matched by age and gender on a 1:1 ratio. Ninety-day postoperative complication rates, day of surgery, and 90-day global period charges and reimbursements were compared between matched cohorts.

RESULTS

A total of 2,369,594 primary TKAs were identified between 2005 and 2014. After age and gender matching, each cohort consisted of 98,555 patients. Hypothyroidism was associated with greater odds of postoperative complications compared to matched controls (odds ratio 1.367, 95% confidence interval 1.322-1.413). The 90-day incidence of multiple postoperative medical and surgical complications, including periprosthetic joint infection, was higher among patients with hypothyroidism. Day of surgery and 90-day episode of care costs were significantly higher in the hypothyroidism cohort.

CONCLUSION

This study demonstrated an increased risk of multiple postoperative complications and higher costs among patients with hypothyroidism following primary TKA. Surgeons should counsel patients on these findings and seek preoperative optimization strategies to reduce these risks and lower costs in this patient population.

Modulating the function of the immune system by thyroid hormones and thyrotropin

Accumulating evidence suggests a close bidirectional communication and regulation between the neuroendocrine and immune systems. Thyroid hormones (THs) can exert responses in various immune cells, e.g., monocytes, macrophages, natural killer cells, and lymphocytes, affecting several inflammation-related processes (such as, chemotaxis, phagocytosis, reactive oxygen species generation, and cytokines production). The interactions between the endocrine and immune systems have been shown to contribute to pathophysiological conditions, including sepsis, inflammation, autoimmune diseases and viral infections. Under these conditions, TH therapy could contribute to restoring normal physiological functions. Here we discuss the effects of THs and thyroid stimulating hormone (TSH) on the immune system and the contribution to inflammation and pathogen clearance, as well as the consequences of thyroid pathologies over the function of the immune system.

Management of the Infected Total Hip Arthroplasty

In the United Kingdom approximately 80,000 total hip arthroplasties are undertaken on an average each year. The popularity and demand for this operation are continually increasing. Our understanding of arthroplasty surgery and its complications has evolved greatly, and as a result infection rates are undeniably at an all-time low. The increasing volume of operations being performed does, however, mean that we still continue to see an increased number of cases of infection. There is no doubt that periprosthetic joint infection (PJI) poses a complex clinical and diagnostic predicament to clinicians. Delay in the diagnosis and treatment of PJI can not only be detrimental in terms of patient morbidity, but it also poses a significant financial burden to health care institutions. It is therefore in the best interest of the patient, surgeon, and institution to optimize the diagnosis and treatment of this devastating complication. There remains considerable variability in terms of approach to diagnosis and treatment of PJI among orthopedic surgeons. In this review, we will, therefore, examine in detail the current body of evidence available on PJI. We will discuss the most robust and up-to-date methods of diagnosis and offer a comparison of management strategies.