Slip and fall injuries represent a significant burden to the Canadian general public and healthcare system; the annual financial cost of these accidents in Canada is estimated to be $2 billion (2014). Interestingly, slip and fall accidents are not evenly distributed across the provinces, with the rate of hospitalization due to falls in Alberta being nearly three times greater than the rate in Ontario. Our research aim was to create the Alberta Slip and Fall Index (ASFI) – a simple scale like the UV or Air Quality index – that could be used to warn the general public about the presence of slippery conditions. The ASFI could be paired with interventions proven to prevent outdoor slips and falls, like promoting the use of ice cleats.

Eleven years (January 2008 - December 2018) of emergency room presentations to the four adult hospitals in Calgary, Alberta were filtered based on the ICD-10 diagnostic code W00 (slip and fall due to ice and snow). Multivariable dispersion-corrected Poisson regression models were used to analyze the weather conditions and time of year most predictive of slip and fall injuries. A slip and fall risk calculator (the ASFI) was designed using output from statistical modelling. To validate the ASFI we compared model predicted slip and fall risk to real presentations using retrospective weather and patient data.

The final dataset included 14,977 slip and fall incidents. The three months with the most emergency room presentations were January(n = 3591), February(n = 2997), and March(n = 2954); each of these predicted increased slip and fall accidents(p < 0 .001). Same day ice was significantly associated with more slip and fall accidents, as was the presence of ice one, two, and three days prior(p < 0 .001). Snow one day prior was mildly protective against slip and fall accidents, but this effect was not significant(p = 0.861). Snow, ice, and time of year variables can be input into the ASFI calculator, which computes the likelihood of slip and fall accidents on a 0-40 point scale, with 40 indicating maximum fall risk. Upon validation of the ASFI, we generally found days with the highest raw frequency of slip and fall accidents had higher ASFI scores. Although the ASFI can theoretically result in a score of 40, when we entered realistic weather conditions it was impossible to create a score higher than 20.

The ASFI represents a tool that can be used to prevent slip and fall accidents due to icy and snowy conditions. As demonstrated by our inability to maximize the risk score when using realistic weather conditions, the ASFI is imperfect. Despite its shortcomings, the ASFI is a preliminary step towards effectively disseminating information about the weather conditions likely to lead to falls. Ideally, a refined ASFI will help people better understand when to use protective equipment and take extra precaution outdoors. If implementing the ASFI led to even a 1% decrease in injuries caused by falls, the annual Canadian healthcare savings would be roughly $2 million.

Glenoid failure remains the most common mode of total shoulder arthroplasty failures. Porous tantalum metal (Trabecular Metal™, Zimmer) have grown in popularity in hip and knee arthroplasty. First-generation porous tantalum metal-backed glenoid components demonstrated metal debris, resulted in failure, and were revised to second-generation glenoid implants. Evidence for second-generation porous tantalum metal implants in shoulder arthroplasty is sparse.1–4 The purpose of this study was to assess clinical and radiographic outcomes in a series of patients with second-generation porous tantalum glenoid components at a minimum two-years postoperative.

We retrospectively reviewed the clinical and radiographic outcomes of patients who received a second-generation porous tantalum glenoid component anatomic shoulder arthroplasty between May 2009 and December 2017 with minimum 24 months follow-up. The shoulder arthroplasties were performed by one of two senior fellowship-trained surgeons. We collected postoperative clinical outcome indicators: EQ5D visual analog scale (VAS), Western Ontario Osteoarthritis of the Shoulder (WOOS) Index, American Shoulder and Elbow Surgeons (ASES) Score, and Constant Score (CS). Radiographic review was performed by an independent fellowship-trained surgeon. The Endrizzi metal debris grading system1 was utilized to grade metal debris. We computed descriptive statistics and compared outcome scores between groups via the non-parametric Wilcoxon rank-sum test, with group-wise comparisons defined by: metal debris and humeral head migration (secondary analyses).

Thirty-five patients [23 male (65.7%) and 12 female (34.3%)] with 40 shoulder replacements participated in the study. Forty of 61 shoulders (65.6%) had an average of 64 ± 20.3 months follow-up (range 31 to 95). Average BMI was 27.5 ± 4.4 kg/m2 (range 19.5 to 39.1). The average postoperative EQ5D VAS at final follow-up was 74.6 ± 22.5, WOOS Index 87.9 ± 16.6, ASES Score 88.3 ± 10.9, and CS 80.4 ± 13. At final follow-up, 18 of 40 shoulders (45%) had metal debris [15 of 40 (37.5%) Endrizzi grade 1 and three of 40 (7.5%) Endrizzi grade 2], and 22 of 40 shoulders (55%) did not show evidence of metal debris. There was one non-revision reoperation (open subscapularis exploration), one shoulder with anterosuperior escape, three shoulders with glenoid radiolucencies indicative of possible glenoid loosening, and nine shoulders with superior migration of the humeral head (>2mm migration at final follow-up compared to immediate postoperative). When comparing postoperative scores between patients with vs without metal debris, we found no statistically significant difference in the EQ5D VAS, WOOS Index, ASES Score and CS. On further analyses, when comparing superior migration of the humeral head and postoperative outcomes scores, we found no statistically significant difference.

We report the longest published follow-up with clinical and radiographic outcomes of second-generation porous tantalum glenoid anatomic shoulder arthroplasties. In this series of patients, 45% of total shoulder arthroplasties with a second-generation porous tantalum glenoid implant had radiographic evidence of metal debris. This metal debris was not statistically associated with poorer postoperative outcomes. Further investigation and ongoing follow-up are warranted.

Revision surgery is an important outcome of hip and knee arthroplasty among patients with osteoarthritis (OA). The objective of this study was to determine the risk of revision over time in a large, geographically defined population in North America, and to assess the effects of age, sex, and socioeconomic status (SES) on knee and hip revision rates in this population.

We used data on admissions to all acute care hospitals in British Columbia (BC), Canada (population of four million people) from 1986 until 2004 (eighteen years of follow-up). Primary knee and hip replacement surgery for OA and revision procedures were identified using diagnostic (ICD-9, ICD-10) codes and surgical procedure codes. We excluded cases admitted due to injury or neoplasm. SES was assigned based on residential address linked to census data at the level of enumeration area (ecological variable), and analyzed according to quintiles or deciles of the distribution. In the analysis, we used Kaplan-Meier survival curves to describe the risk of first revision following first primary replacement surgery over time and parametric (Weibull) survival regression models to analyze the effects of joint (hip vs. knee) age, sex, and SES on revision rates. Death, emigration, and another primary joint replacement were treated as censoring events.

Between 1986 and 2004, we observed 24,169 first primary hip replacements and 22,875 first primary knee replacements. In these patients, there were 1,313 hip revisions and 914 knee revisions following a primary replacement. The risk of revision at five, ten and fifteen years after primary replacement according to joint and sex were identified The overall risks were 10.1% for the hip and 8.7% for the knee at ten years, and 15.5% and 14.7%, respectively, at fifteen years. Risk of revision (%) following first primary joint replacement surgery Hip Knee Years Men Women Men Women 5 5.0 3.9 4.6 3.8 10 11.0 9.4 9.7 8.0 15 17.8 14.1 18.5 12.4 In a multivariate survival regression model including joint, age, sex, and SES, only age and sex were significantly associated with revisions. The hazard ratio was 1.2 for men compared with women (p< 0.0001). Revision rates were higher in younger persons, with hazard ratios increasing from 1.7 for age 70–79 (p< 0.0001) to 3.9 for age < 49 (p< 0.0001) compared with age 80+. After adjusting for age and sex, SES was not significantly associated with revision risk following primary hip or knee replacement surgery in this population (p=0.75).

This is one of the largest and longest cohort studies in North America to look at the epidemiology of revision procedures following hip and knee replacement for OA. Higher rates in men and in younger persons are consistent with previous reports. The lack of association between revision risk and SES in BC is an important finding given current concerns about socioeconomic disparities in access to and outcomes of treatment for OA.