The purpose of this population-based study was to determine the association between morbid obesity and 10-year mortality and complications in patients undergoing primary THA.

A cohort study of 22,251 patients, aged 45–74 years old, treated with primary THA between 2002 and 2007 for osteoarthritis, was conducted using Ontario administrative healthcare databases. Patients were followed for 10 years. Risk ratios (RRs) of mortality, reoperation, revision, and dislocation in patients with body mass index (BMI) > 45 kg/m2(morbidly obese patients) compared with BMI ≤45 kg/m2 (non-morbidly obese) were estimated.

3.3% of the cohort (726) was morbidly obese. Morbidly obese patients were younger (mean age 60.6 vs. 63.3, P-value < 0 .001) and more likely to be female (63.9% vs. 52.2%, P-value < 0 .001), compared with non-morbidly obese patients. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% CI 1.18, 1.62). Risks of revision (RR 1.43, 95% CI 0.96, 2.13) and dislocation (RR 2.38, 95% CI 1.38, 4.10) were higher in morbidly obese men, compared with non-morbidly obese men, there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women, compared to non-morbidly obese women (RR 1.60, 95% CI 1.05, 2.40), there was no association between obesity and reoperation in men.

Morbidly obese patients undergoing primary THA are at higher risks of long-term mortality and complications. There were differences in complication risk by sex. Results should inform evidence-based perioperative counseling of morbidly obese patients considering THA.

Necrotizing Fasciitis (NF) is a life-threatening infectious condition which requires expedient diagnosis to proceed with urgent surgical debridement. However, it can be difficult to establish an early diagnosis and expedite operative management as signs and symptoms are often non-specific and may mimic other pathology. Scoring systems such as The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) have been proposed to incorporate laboratory findings to predict whether a soft tissue infection is likely to be NF. Recent studies have found the sensitivity and specificity of the LRINEC tool to be lower than originally cited by the LRINEC authors in a validation cohort. Furthermore, there seems to be a predilection for certain geographic locations of patients with NF transferred to our tertiary care center for management, however, to our knowledge, geographic risk factors for NF have not been reported. This study also aims to determine the morbidity and mortality rate of NF at our Canadian tertiary hospital in recent years.

Comorbidities such as smoking, diabetes, and steroid use will be analyzed for any correlation with developing NF. Identification of patient factors in correlation with laboratory values may help identify patients at higher risk for having NF upon their presentation to the emergency department. A resultant earlier diagnosis of necrotizing soft tissue infections would allow for earlier surgical debridement and positively influence patient outcomes.

A retrospective chart review of 125 cases of NF at Kingston Health Sciences Centre from 2005 to 2017 was carried out to assess the validity of the LRINEC in our population and to examine the effect of comorbid factors such as smoking, diabetes, and corticosteroid use on the development of NF. The study cohort included patients treated by all surgical disciplines at our institution over twelve years. A separate cohort of 125 cellulitis or abscess cases was analyzed to assess the validity of the LRINEC tool in differentiating necrotizing fasciitis from non-necrotizing infections such as cellulitis and soft tissue abscess.

The 30-day mortality rate of NF treated at our institution during the study period was 21%. Advanced age was found to be a significant risk factor for death within 30 days of diagnosis (p=0.001). Smoking and steroid use were both found to increase risk for developing NF (p=0.01 and p=0.03, respectively). Diabetes did not appear to increase risk NF. There was no statistical difference in mortality rates between males and females with NF. The sensitivity of LRINEC in detecting NF was only 47% with a specificity of 74%.

The mortality rate of NF at our center is similar to that of other countries in recent years. Males and females have nearly equal mortality rates from NF. Smoking and steroid use appear to increase risk for developing NF, while diabetes may not. The LRINEC assessment tool alone may underestimate risk for developing NF, however, use of other clinical factors such as comorbidity analysis will further aide in the diagnosis of NF allowing for earlier surgical debridement.

Purpose

Adenosine triphosphate (ATP) has been implicated as an autocrine/paracrine signal in the mechanotransduction pathway of chondrocytes. In this study, human chondrocytes in a 3D agarose scaffold were cultured with exogenous ATP in varying doses to determine its effect on extracellular matrix synthesis by the cells. Further experiments determined basal ATP release, ATP degradation and expression of P2Y1 and P2Y2 purinoreceptors by the cultured cell constructs.