Aims

This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

Total hip arthroplasty (THA) is performed under general anesthesia (GA) or spinal anesthesia (SA). The first objective of this study was to determine which patient factors are associated with receiving SA versus GA. The second objective was to discern the effect of anesthesia type on short-term postoperative complications and readmission. The third objective was to elucidate factors that impact the effect of anesthesia type on outcome following arthroplasty.

This retrospective cohort study included 108,905 patients (median age, 66 years; IQR 60-73 years; 56.0% females) who underwent primary THA for treatment of primary osteoarthritis in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database during the period of 2013-2018. Multivariable logistic regression analysis was performed to evaluate variables associated with anesthesia type and outcomes following arthroplasty.

Anesthesia type administered during THA was significantly associated with race. Specifically, Black and Hispanic patients were less likely to receive SA compared to White patients (White: OR 1.00; Black: OR 0.73; 95% confidence interval [CI] 0.71-0.75; Hispanic: OR 0.81; CI, 0.75-0.88), while Asian patients were more likely to receive SA (OR 1.44, CI 1.31-1.59). Spinal anesthesia was associated with increased age (OR 1.01; CI 1.00-1.01). Patients with less frailty and lower comorbidity were more likely to receive SA based on the modified frailty index ([mFI-5]=0: OR 1.00; mFI-5=1: OR 0.90, CI 0.88-0.93; mFI-5=2 or greater: OR 0.86, CI 0.83-0.90) and American Society of Anesthesiologists (ASA) class (ASA=1: OR 1.00; ASA=2: OR 0.85, CI 0.79-0.91; ASA=3: OR 0.64, CI 0.59-0.69; ASA=4-5: OR 0.47; CI 0.41-0.53). With increased BMI, patients were less likely to be treated with SA (OR 0.99; CI 0.98-0.99).

Patients treated with SA had less post-operative complications than GA (OR 0.74; CI 0.67-0.81) and a lower risk of readmission than GA (OR 0.88; CI 0.82-0.95) following THA. Race, age, BMI, and ASA class were found to affect the impact of anesthesia type on post-operative complications. Stratified analysis demonstrated that the reduced risk of complications following arthroplasty noted in patients treated with SA compared to GA was more pronounced in Black, Asian, and Hispanic patients compared to White patients. Furthermore, the positive effect of SA compared to GA was stronger in patients who had reduced age, elevated BMI, and lower ASA class.

Among patients undergoing THA for management of primary osteoarthritis, factors including race, BMI, and frailty appear to have impacted the type of anesthesia received. Patients treated with SA had a significantly lower risk of readmission to hospital and adverse events within 30 days of surgery compared to those treated with GA. Furthermore, the positive effect on outcome afforded by SA was different between patients depending on race, age, BMI, and ASA class. These findings may help to guide selection of anesthesia type in subpopulations of patients undergoing primary THA.

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimise exposure on the wards. In order to maintain throughput of elective cases, our hospital was forced to convert as many cases as possible to same day procedures rather than overnight admission. In this retrospective analysis we review the cases performed as same day arthroplasty surgeries compared to the same period 12 months previous.

We conducted a retrospective analysis of patients undergoing total hip and knee arthroplasties in a three month period between October and December in 2019 and again in 2020, in the middle of the SARS-CoV-2 pandemic. Patient demographics, number of out-patient primary arthroplasty cases, length of stay for admissions, 30-day readmission and complications were collated.

In total, 428 patient charts were reviewed for the months of October-December of 2019 (n=195) and 2020 (n=233). Of those, total hip arthroplasties comprised 60% and 58.8% for 2019 and 2020, respectively. Demographic data was comparable with no statistical difference for age, gender contralateral joint replacement or BMI. ASA grade I was more highly prevalent in the 2020 cohort (5.1x increase, n=13 vs n=1). Degenerative disc disease and fibromyalgia were less significantly prevalent in the 2020 cohort. There was a significant increase in same day discharges for non-DAA THAs (2x increase) and TKA (10x increase), with a reciprocal decrease in next day discharges. There were significantly fewer reported superficial wound infections in 2020 (5.6% vs 1.7%) and no significant differences in readmissions or emergency department visits (3.1% vs 3.0%).

The SARS-CoV-2 pandemic meant that hospitals and patients were hopeful to minimise the exposure to the wards and to not put strain on the already taxed in-patient beds. With few positives during the Coronavirus crisis, the pandemic was the catalyst to speed up the outpatient arthroplasty program that has resulted in our institution being more efficient and with no increase in readmissions or early complications.

There is limited literature on the effects of socioeconomic factors on outcomes after total ankle arthroplasty (TAA). In the setting of hip or knee arthroplasty, patients of a lower socioeconomic status demonstrate poorer post-operative satisfaction, longer lengths of stay, and larger functional limitations. It is important to ascertain whether this phenomenon is present in ankle arthritis patients. This is the first study to address the weight of potential socioeconomic factors in affecting various socioeconomic classes, in terms of how they benefit from ankle arthroplasty.

This is retrospective cohort study of 447 patients who underwent a TAA. Primary outcomes included pre-operative and final follow-up AAOS pain, AAOS disability, and SF-36 scores. We then used postal codes to determine median household income using Canadian 2015 census data. Incomes were divided into five groups based on equal amounts over the range of incomes. This method has been used to study medical conditions such as COPD and cardiac disease. These income groups were then compared for differences in outcome measures. Statistical analysis was done using unpaired t-test.

A total of 447 patients were divided into quintiles by income. From lowest income to highest income, the groups had 54, 207, 86, 64, and 36 patients, respectively. The average time from surgery to final follow up was 85.6 months. Interestingly, we found that patients within the middle household income groups had significantly lower AAOS disability scores compared to the lowest income groups at final follow-up (26.41 vs 35.70, p=0.035). Furthermore, there was a trend towards middle income households and lower post-operative AAOS pain scores compared to the lowest income group (19.57 vs 26.65, p=0.063). There was also a trend toward poorer AAOS disability scores when comparing middle income groups to high income groups post-operatively (26.41 vs 32.27, p=0.058). Pre-operatively, patients within the middle-income group had more pain, compared to the lowest and the highest income groups. No significant differences in SF-36 scores were observed. There were no significant differences seen in middle income groups compared to the highest income group for AAOS pain post-operatively. There were no significant differences found in pre-operative AAOS disability score between income groups.

Patients from middle income groups who have undergone TAA demonstrate poorer function and possibly more pain, compared to lower and higher income groups. This suggests that TAA is a viable option for lower socioeconomic groups and should not be a source of discouragement for surgeons. In this circumstance there is no real disparity between the rich and the poor. Further investigation is needed to explore reasons for diminished performance in middle class patients.

The prevalence of alcohol and opioids in severely injured patients has been widely reported from 30-80%. However, despite the increasing global misuse of stimulant drugs, there is a paucity of literature regarding the presence of stimulant drugs in trauma patients. The primary aim of this study was to define the prevalence of stimulant drugs that were detected in patients who presented to Level One Trauma Centers throughout North America, and their effect on length of stay and mortality.

Our triage criteria for admittance to the regional trauma centre are based on the recommendations by the American College of Surgeons Committee on Trauma, who now recommend toxicology screening on every patient. This was a retrospective analysis of data from the Trauma Quality Improvement Program, including all patients presenting emergently to participating Level 1 Trauma Centers from January 2017 to December 2018. A stimulant drug was defined as the detection of cocaine, amphetamine, or methamphetamine. Adults aged 18-64 years were included. Patient risk factors were included adjusted for in the analysis: age, sex, body mass index (BMI), alcohol screening results and smoking status. Univariate analysis was performed for all variables. Multivariable logistic regression and liner regression were used for mortality and length of stay, respectively.

Of a total of 110,561 patients included in the study, 15,958 patients (14.4%) had positive screens for stimulants. The average age in the stimulants cohort was 40.8 years, with a 77.6% male preponderance, BMI of 26.9, blood alcohol content of 0.07, and ISS of 11.3. The control cohort was comparable, though 71.1% male (p<0.001) Patients who tested positive for stimulants had 1.79 times (95% CI, 1.09-2.93) the odds of dying in the emergency department as the control group (p=0.02). Following transfer from the emergency department, the odds ratio for deaths in hospital (OR=1.02, 95% CI 0.90-1.15) was comparable to the control group (p=0.78). The mean length of stay was significantly higher in the stimulant group (2.84 days) compared to the control group (1.79 days) (p<.001). In the Intensive Care Unit, length of stay was 0.64 days in the stimulant group versus 1.65 in the control (p=0.48).

Stimulant misuse is a relevant issue in the trauma population, associated with a longer hospital stay and higher mortality in the emergency department. The continued routine drug screening of trauma patients may be beneficial in trauma centers, to implement preventative measures and optimise resource allocation.

Aims

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimize exposure on wards. In order to maintain throughput of elective cases, our hospital (St Michaels Hospital, Toronto, Canada) was forced to convert as many cases as possible to same-day procedures rather than overnight admission. In this retrospective analysis, we review the cases performed as same-day arthroplasty surgeries compared to the same period in the previous 12 months.

Aims

While preoperative bloodwork is routinely ordered, its value in determining which patients are at risk of postoperative readmission following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is unclear. The objective of this study was to determine which routinely ordered preoperative blood markers have the strongest association with acute hospital readmission for patients undergoing elective TKA and THA.

Aims

The rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA.

Over 300,000 total hip arthroplasties (THA) are performed annually in the USA. Surgical Site Infections (SSI) are one of the most common complications and are associated with increased morbidity, mortality and cost. Risk factors for SSI include obesity, diabetes and smoking, but few studies have reported on the predictive value of pre-operative blood markers for SSI. The purpose of this study was to create a clinical prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of THA based on commonly ordered pre-operative lab markers and using data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

All adult patients undergoing an elective unilateral THA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was used to determine coefficients, with manual stepwise reduction. Receiver Operating Characteristic (ROC) curves were also graphed. The SSI prediction model included the following covariates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphate, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. Since the data met logistic assumption requirements, bootstrap estimation was used to measure internal validity. The area under the ROC curve for final derivations along with McFadden's R-squared were utilized to compare prediction models.

A total of 130,619 patients were included with the median age of patients at time of THA was 67 years (mean=66.6+11.6 years) with 44.8% (n=58,757) being male. A total of 1,561 (1.20%) patients had a superficial or deep SSI (overall SSI). Of all SSI, 45.1% (n=704) had a deep SSI and 55.4% (n=865) had a superficial SSI. The incidence of SSI occurring annually decreased from 1.44% in 2011 to 1.16% in 2016. Area under the ROC curve for the SSI prediction model was 0.79 and 0.78 for deep and superficial SSI, respectively and 0.71 for overall SSI. CHF had the largest effect size (Odds Ratio(OR)=2.88, 95% Confidence Interval (95%CI): 1.56 – 5.32) for overall SSI risk. Albumin (OR=0.44, 95% CI: 0.37 – 0.52, OR=0.31, 95% CI: 0.25 – 0.39, OR=0.48, 95% CI: 0.41 – 0.58) and sodium (OR=0.95, 95% CI: 0.93 – 0.97, OR=0.94, 95% CI: 0.91 – 0.97, OR=0.95, 95% CI: 0.93 – 0.98) levels were consistently significant in all clinical prediction models for superficial, deep and overall SSI, respectively. In terms of pre-operative blood markers, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI.

In this large NSQIP database study, we were able to create an SSI prediction model and identify risk factors for predicting acute superficial, deep and overall SSI after THA. To our knowledge, this is the first clinical model whereby pre-operative hyponatremia (in addition to hypoalbuminemia) levels have been predictive of SSI after THA. Although the model remains without external validation, it is a vital starting point for developing a risk prediction model for SSI and can help physicians mitigate risk factors for acute SSI post THA.

Distracted driving is now the number one cause of death among teenagers in the United States of America according to the National Highway Traffic Safety Administration. However, the risks and consequences of driving while distracted spans all ages, gender, and ethnicity. The Distractions on the Road: Injury eValuation in Surgery And FracturE Clinics (DRIVSAFE) Study aimed to examine the prevalence of distracted driving among patients attending hospital-based orthopaedic surgery fracture clinics. We further aimed to explore factors associated with distracted driving.

In a large, multi-center prospective observational study, we recruited 1378 adult patients with injuries treated across four clinics (Hamilton, Ontario, Toronto, Ontario, Calgary, Alberta, Halifax, Nova Scotia) across Canada. Eligible patients included those who held a valid driver's license and were able to communicate and understand written english. Patients were administered questions about distracted driving. Data were analyzed with descriptive statistics.

Patients average age was 45.8 years old (range 16 – 87), 54.3% male, and 44.6% female (1.1% not disclosed). Of 1361 patients, 1358 self-reported distracted driving (99.8%). Common sources of distractions included talking to passengers (98.7%), outer-vehicle distractions (95.5%), eating/drinking (90.4%), music listening/adjusting the radio (97.6%/93.8%), singing (83.2%), accepting phone calls (65.6%) and daydreaming (61.2%). Seventy-nine patients (6.3%), reported having been stopped by police for using a handheld device in the past. Among 113 drivers who disclosed the cause of their injury as a motor vehicle crash (MVC), 20 of them (17%) acknowledged being distracted at the time of the crash. Of the participants surveyed, 729 reported that during their lifetime they had been the driver in a MVC, with 226 (31.1%) acknowledging they were distracted at the time of the crash.

Approximately, 1 in 6 participants in this study had a MVC where they reported to be distracted. Despite the overwhelming knowledge that distracted driving is dangerous and the recognition by participants that it can be dangerous, a staggering amount of drivers engage in distracted driving on a fairly routine basis. This study demonstrates an ongoing need for research and driver education to reduce distracted driving and its devastating consequences.

Total knee arthroplasty (TKA) is the most commonly performed elective orthopaedic procedure. With an increasingly aging population, the number of TKAs performed is expected to be ∼2,900 per 100,000 by 2050. Surgical Site Infections (SSI) after TKA can have significant morbidity and mortality. The purpose of this study was to construct a risk prediction model for acute SSI (classified as either superficial, deep and overall) within 30 days of a TKA based on commonly ordered pre-operative blood markers and using audited administrative data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

All adult patients undergoing an elective unilateral TKA for osteoarthritis from 2011–2016 were identified from the NSQIP database using Current Procedural Terminology (CPT) codes. Patients with active or chronic, local or systemic infection/sepsis or disseminated cancer were excluded. Multivariate logistic regression was conducted to estimate coefficients, with manual stepwise reduction to construct models. Bootstrap estimation was administered to measure internal validity. The SSI prediction model included the following co-variates: body mass index (BMI) and sex, comorbidities such as congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), smoking, current/previous steroid use, as well as pre-operative blood markers, albumin, alkaline phosphatase, blood urea nitrogen (BUN), creatinine, hematocrit, international normalized ratio (INR), platelets, prothrombin time (PT), sodium and white blood cell (WBC) levels. To compare clinical models, areas under the receiver operating characteristic (ROC) curves and McFadden's R-squared values were reported.

The total number of patients undergoing TKA were 210,524 with a median age of 67 years (mean age of 66.6 + 9.6 years) and the majority being females (61.9%, N=130,314). A total of 1,674 patients (0.8%) had a SSI within 30 days of the index TKA, of which N=546 patients (33.2%) had a deep SSI and N=1,128 patients (67.4%) had a superficial SSI. The annual incidence rate of overall SSI decreased from 1.60% in 2011 to 0.68% in 2016. The final risk prediction model for SSI contained, smoking (OR=1.69, 95% CI: 1.31 – 2.18), previous/current steroid use (OR=1.66, 95% CI: 1.23 – 2.23), as well as the pre-operative lab markers, albumin (OR=0.46, 95% CI: 0.37 – 0.56), blood urea nitrogen (BUN, OR=1.01, 95% CI: 1 – 1.02), international normalized ratio (INR, OR=1.22, 95% CI:1.05 – 1.41), and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98;). Area under the ROC curve for the final model of overall SSI was 0.64. Models for deep and superficial SSI had ROC areas of 0.68 and 0.63, respectively. Albumin (OR=0.46, 95% CI: 0.37 – 0.56, OR=0.33, 95% CI: 0.27 – 0.40, OR=0.75, 95% CI: 0.59 – 0.95) and sodium levels (OR=0.94, 95% CI: 0.91 – 0.98, OR=0.96, 95% CI: 0.93 – 0.99, OR=0.97, 95% CI: 0.96 – 0.99) levels were consistently significant in all prediction models for superficial, deep and overall SSI, respectively. Overall, hypoalbuminemia and hyponatremia are both significant risk factors for superficial, deep and overall SSI.

To our knowledge, this is the first prediction model for acute SSI post TKA whereby hyponatremia (and hypoalbuminemia) are predictive of SSI. This prediction model can help fill an important gap for predicting risk factors for SSI after TKA and can help physicians better optimize patients prior to TKA.

The purpose of this investigation is to assess the rate of wear the effect once the “bedding in period”/ poly creep had been eliminated. Creep is the visco-elastic deformation that polyethylene exhibits in the first 6–12 weeks. We also assessed the wear pattern of four different bearing couples in total hip arthroplasty (THA): cobalt-chrome (CoCr) versus oxidized zirconium (OxZir) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) versus highly-crosslinked polyethylene (XLPE) acetabular liners.

This was a randomized control study involving 92 patients undergoing THA. They were randomized to one of four bearing couples: (1) CoCr/UHMWPE (n= 23), (2) OxZir/UHMWPE (n=21), (3) CoCr/XLPE (n=24), (4) OxZir/XLPE (n=24). Patients underwent a posterior approach from one of three surgeons involved in the study. All patients received a porous-coated cementless acetabular shell and a cylindrical proximally coated stem with 28 mm femoral heads. Each patient was reviewed clinically and radiographically at six weeks, three and 12 months, two, five and 10 years after surgery. Standardized anteroposterior and lateral radiographs were taken. All polyethylene wear was measured by an independent blinded reviewer. Linear and volumetric wear rates were measured on radiographs using a validated computer software (Polyware Rev. 5). Creep was defined as the wear at 6 or 12 weeks, depending on if there was a more than 10% difference between both measurements. If a greater than 10% difference occurred than the later period's wear would be defined as creep.

72 hips were included in analysis after exclusion of seven revisions, three deaths and 10 losses to follow-up. The annual linear wear rates (in mm/y) at 10 years were (1) 0.249, (2) 0.250, (3) 0.074 and (4) 0.050. After adjusting for creep these rates become were (1) 0.181, (2) 0.142, (3) 0.040 and (4) 0.023. There is statistical differences between raw and adjusted linear wear rates for all bearing couples. The percentage of the radiographically measured wear at 10 years due to creep is (1) 30% (2) 44%, (3) 58.5% and (4) 51.5% with significant differences in couples with XLPE versus those with UHMWPE. There was no significant correlation between age, gender, cup size, tilt, planar anteversion and the linear or volumetric wear rates.

The linear wear rate of both UHMWPE and XLPE are even lower thxdsxzan previously described when creep is factored out. XLPE has again demonstrated far superior linear wear rates at 10 years than UHMWPE. There were no significant differences in wear rate at 10 years between CoCr and OxZir, this may be due to an underpowered study. XLPE exhibits proportionally more creep than UHMWPE within the first 6–12 weeks and accounts for more of the total wear at 10 years as measured radiographically at the end period.

A randomized trial was designed to compare the outcome of ceramic-on-ceramic with ceramic on conventional polyethylene. These patients have been followed for 15 years.

58 hips in 57 patients under 60 years of age were randomized into one of two groups. Patients were blinded to the type of hip they received. Both groups of patients were treated routinely with prophylactic peri-operative antibiotics and low molecular weight Heparin. All patients were seen at six weeks, three months and annually after surgery. Clinical and radiologic assessment was carried out at each visit.

Fifty-eight hips were available for analysis, 28 in the CoP group and 29 patients in the CoC group. Mean age of both groups was less than 45 years.

There were seven revisions (16%) among the 58 patients enrolled in the study. In the CoP group four patients underwent revision with head and liner exchange for eccentric polyethylene wear 16 years post-implantation. In the CoC group one patient had a cup revision at 15 years for acute aseptic instability of the acetabulum; two additional patients in the CoC group had femoral head exchange, one for fracture and one for trunnion corrosion. Both occurred 14 years after the index surgery.

Functional outcome scores showed no difference between the two groups at 15 years. Radiographically there was a statistically difference in wear between the two groups.

This study demonstrates that both ceramic-on-ceramic and ceramic-on-polyethylene produce satisfactory functional results with low revision rates in young patients.