With the rising rates, and associated costs, of total knee arthroplasty (TKA), enhanced clarity regarding patient appropriateness for TKA is warranted. Towards addressing this gap, we elucidated in qualitative research that surgeons and osteoarthritis (OA) patients considered TKA need, readiness/willingness, health status, and expectations of TKA most important in determining patient appropriateness for TKA. The current study evaluated the predictive validity of pre-TKA measures of these appropriateness domains for attainment of a good TKA outcome.

This prospective cohort study recruited knee OA patients aged 30+ years referred for TKA at two hip/knee surgery centers in Alberta, Canada. Those receiving primary, unilateral TKA completed questionnaires pre-TKA assessing TKA need (WOMAC-pain, ICOAP-pain, NRS-pain, KOOS-physical function, Perceived Arthritis Coping Efficacy, prior OA treatment), TKA readiness/willingness (Patient Acceptable Symptom State (PASS), willingness to undergo TKA), health status (PHQ-8, BMI, MSK and non-MSK comorbidities), TKA expectations (HSS KR Expectations survey items) and contextual factors (e.g., age, gender, employment status). One-year post-TKA, we assessed for a ‘good outcome’ (yes/no), defined as improved knee symptoms (OARSI-OMERACT responder criteria) AND overall satisfaction with TKA results. Multiple logistic regression, stepwise variable selection, and best possible subsets regression was used to identify the model with the smallest number of independent variables and greatest discriminant validity for our outcome. Receiver Operating Characteristic (ROC) curves were generated to compare the discriminative ability of each appropriateness domain based on the ‘area under the ROC curve’ (AUC). Multivariable robust Poisson regression was used to assess the relationship of the variables to achievement of a good outcome.

f 1,275 TKA recipients, 1,053 (82.6%) had complete data for analyses (mean age 66.9 years [SD 8.8]; 58.6% female). Mean WOMAC pain and KOOS-PS scores were 11.5/20 (SD 3.5) and 52.8/100 (SD 17.1), respectively. 78.1% (95% CI 75.4–80.5%) achieved a good outcome. Stepwise variable selection identified optimal discrimination was achieved with 13 variables. The three best 13-variable models included measures of TKA need (WOMAC pain, KOOS-PS), readiness/willingness (PASS, TKA willingness), health status (PHQ-8, troublesome hips, contralateral knee, low back), TKA expectations (the importance of improved psychological well-being, ability to go up stairs, kneel, and participate in recreational activities as TKA outcomes), and patient age. Model discrimination was fair for TKA need (AUC 0.68, 95% CI 0.63-0.72), TKA readiness/willingness (AUC 0.61, 95% CI 0.57-0.65), health status (AUC 0.59, 95% CI 0.54-0.63) and TKA expectations (AUC 0.58, 95% CI 0.54-0.62), but the model with all appropriateness variables had good discrimination (AUC 0.72, 95% CI 0.685-0.76). The likelihood of achieving a good outcome was significantly higher for those with greater knee pain, disability, unacceptable knee symptoms, definite willingness to undergo TKA, less depression who considered improved ability to perform recreational activities or climb stairs ‘very important’ TKA outcomes, and lower in those who considered it important that TKA improve psychological wellbeing or ability to kneel.

Beyond surgical need (OA symptoms) and health status, assessment of patients’ readiness and willingness to undergo, and their expectations for, TKA, should be incorporated into assessment of patient appropriateness for surgery.

Immigrated Canadians make up approximately 20% of the total population in Canada, and 30% of the population in Ontario. Despite universal health coverage and an equal prevalence of severe arthritis in immigrants relative to non-immigrants, the former may be underrepresented amongst arthroplasty recipients secondary to challenges navigating the healthcare system. The primary aim of this study was to determine if utilization of arthroplasty differs between immigrant populations and persons born in Canada. The secondary aim was to determine differences in outcomes following total hip and knee arthroplasty (THA and TKA, respectively).

This is a retrospective population-based cohort study using health administrative databases. All patients aged ≥18 in Ontario who underwent their first primary elective THA or TKA between 2002 and 2016 were identified. Immigration status for each patient was identified via linkage to the ‘Immigration, Refugee and Citizenship Canada’ database. Outcomes included all-cause and septic revision surgery within 12-months, dislocation (for THA) and total post-operative case cost and were compared between groups. Cochrane-Armitage Test for Trend was utilized to determine if the uptake of arthroplasty by immigrants changed over time.

There was a total of 186,528 TKA recipients and 116,472 THA recipients identified over the study period. Of these, 10,193 (5.5%) and 3,165 (2.7%) were immigrants, respectively. The largest proportion of immigrants were from the Asia and Pacific region for those undergoing TKA (54.0%) and Europe for THA recipients (53.4%). There was no difference in the rate of all-cause revision or septic revision at 12 months between groups undergoing TKA (p=0.864, p=0.585) or THA (p=0.527, p=0.397), respectively. There was also no difference in the rate of dislocations between immigrants and people born in Canada (p=0.765, respectively).

Despite having similar complication rates and costs, immigrants represent a significantly smaller proportion of joint replacement recipients than they represent in the general population in Ontario. These results suggest significant underutilization of surgical management for arthritis among Canada's immigrant populations. Initiatives to improve access to total joint arthroplasty are warranted.

The primary objective is to compare revision rates for lumbar disc replacement (LDR) and fusion at the same or adjacent levels in Ontario, Canada. The secondary objectives include acute complications during hospitalization and in 30 days, and length of hospital stay.

A population-based cohort study was conducted using health administrative databases including patients undergoing LDR or single level fusion between October 2005 to March 2018. Patients receiving LDR or fusion were identified using physician claims recorded in the Ontario Health Insurance Program database. Additional details of surgical procedure were obtained from the Canadian Institute for Health Information hospital discharge abstract. Primary outcome measured was presence of revision surgery in the lumbar spine defined as operation greater than 30 days from index procedure. Secondary outcomes were immediate/ acute complications within the first 30 days of index operation.

A total of 42,024 patients were included. Mean follow up in the LDR and fusion groups were 2943 and 2301 days, respectively. The rates of revision surgery at the same or adjacent levels were 4.7% in the LDR group and 11.1% in the fusion group (P=.003). Multivariate analysis identified risk factors for revision surgery as being female, hypertension, and lower surgeon volume. More patients in the fusion group had dural tears (p<.001), while the LDR group had more “other” complications (p=.037). The LDR group had a longer mean hospital stay (p=.018).

In this study population, the LDR group had lower rates of revision compared to the fusion group. Caution is needed in concluding its significance due to lack of clinical variables and possible differences in indications between LDR and posterior decompression and fusion.

Demand for total knee arthroplasty (TKA) is increasing as it remains the gold-standard treatment for end-stage osteoarthritis (OA) of the knee. While magnetic-resonance imaging (MRI) scans of the knee are not indicated for diagnosing knee OA, they are commonly ordered prior to the referral to an orthopaedic surgeon. The purpose of this study was to determine the proportion of patients who underwent an MRI in the two years prior to their primary TKA for OA. Secondary outcomes included determining patient and physician associations with increased MRI usage.

This is a population-based cohort study using billing codes in Ontario, Canada. All patients over 40 years-old who underwent a primary TKA between April 1, 2008 and March 31, 2017 were included. Statistical analyses were performed using SAS and included the Cochran-Armitage test for trend of MRI prior to surgery, and predictive multivariable regression model. Significance was set to p<0.05.

There were 172,689 eligible first-time TKA recipients, of which 34,140 (19.8%) received an MRI in the two years prior to their surgery. The majority of these (70.8%) were ordered by primary care physicians, followed by orthopaedic surgeons (22.5%). Patients who received an MRI were younger and had fewer comorbidities than patients who did not (p<0.001). MRI use prior to TKA increased from 15.9% in 2008 to 20.1% in 2017 (p<0.0001).

Despite MRIs rarely being indicated for the work-up of knee OA, nearly one in five patients have an MRI in the two years prior to their TKA. Reducing the use of this prior to TKA may help reduce wait-times for surgery.

Total knee and hip arthroplasty (TKA and THA) are two of the highest volume and resource intensive surgical procedures. Key drivers of the cost of surgical care are duration of surgery (DOS) and postoperative inpatient length of stay (LOS). The ability to predict TKA and THA DOS and LOS has substantial implications for hospital finances, scheduling and resource allocation. The goal of this study was to predict DOS and LOS for elective unilateral TKAs and THAs using machine learning models (MLMs) constructed on preoperative patient factors using a large North American database.

The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for elective unilateral TKA and THA procedures from 2014-2019. The dataset was split into training, validation and testing based on year. Multiple conventional and deep MLMs such as linear, tree-based and multilayer perceptrons (MLPs) were constructed. The models with best performance on the validation set were evaluated on the testing set. Models were evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer of the actual target), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure useful predictions, the results of the models were compared to a mean regressor.

A total of 499,432 patients (TKA 302,490; THA 196,942) were included. The MLP models had the best MSEs and accuracy across both TKA and THA patients. During testing, the TKA MSEs for DOS and LOS were 0.893 and 0.688 while the THA MSEs for DOS and LOS were 0.895 and 0.691. The TKA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 78.8% and 88.3%, while the TKA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 75.2% and 76.1%. The THA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 81.6% and 91.4%, while the THA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 78.3% and 80.4%. All models across both TKA and THA patients were more accurate than the mean regressors for both DOS and LOS predictions across both buffer and classification accuracies.

Conventional and deep MLMs have been effectively implemented to predict the DOS and LOS of elective unilateral TKA and THA patients based on preoperative patient factors using a large North American database with a high level of accuracy. Future work should include using operational factors to further refine these models and improve predictive accuracy. Results of this work will allow institutions to optimize their resource allocation, reduce costs and improve surgical scheduling.

Echocardiography is commonly used in hip fracture patients to evaluate perioperative cardiac risk and identify cardiac abnormalities. However, echocardiography that delays surgical repair may be harmful. The objective of this study was to compare mortality, surgical wait times, length of stay (LOS), and health care costs for similar hip fracture patients managed with and without preoperative echocardiograms.

A population based, retrospective cohort study of all hip fracture patients (>age 45) in Ontario, Canada was conducted. The primary exposure was pre-operative echocardiography (between hospital admission and surgery). Patients receiving preoperative echocardiograms were matched to those without using a propensity score incorporating patient demographic information, comorbidity status, and provider information. Mortality rates, surgical wait times, post-operative length of stay (LOS), and medical costs (expressed as 2013$ CAN) up to 1-year post-operatively were assessed after matching.

There were 2354 (∼5.6%) of 42,230 eligible hip fracture patients that received a preoperative echocardiogram during the study period. After successfully matching 2298 (∼97.6%) patients, echocardiography was associated with significant increases in mortality at 90 days (20.1% vs. 16.8%, p=0.004) and 1 year (32.9% vs. 27.8%, p < 0 .001), but not 30-days (11.4% vs. 9.8%, p=0.084). Patients with echocardiography also had an increased (mean ± SD) delay (in hours) from presentation to surgery (68.80 ± 44.23 hours vs. 39.69 ± 27.09 hours, p < 0 .001) and only 38.1% of patients had surgery within 48 hours. Total LOS (in days) (mean 19.49 ± 25.39 days vs. 15.94 ± 22.48 days, p < 0 .001) and total healthcare costs at 1 year (mean: $51,714.69 ± 54,675.28 vs. $41,861.47 ± 50,854.12, p < 0 .001) were also increased. There was wide variability in echocardiography ordering practice in Ontario, with a range of 0% to 22.97% of hip fracture patients undergoing preoperative echocardiography at different hospital sites.

Preoperative echocardiography for hip fracture patients is associated with increased postoperative mortality. It is also associated with increased surgical delay, post-operative LOS, and total health care costs at 1 year. Echocardiography should be considered an urgent test when ordered to prevent additional surgical delay, and further research is necessary to clarify indications for this common preoperative investigation.

Echocardiography is commonly used in hip fracture patients to evaluate perioperative cardiac risk and identify cardiac abnormalities. However, echocardiography that delays surgical repair may be harmful. The objective of this study was to compare mortality, surgical wait times, length of stay (LOS), and health care costs for similar hip fracture patients managed with and without preoperative echocardiography.

A population based, retrospective cohort study of all hip fracture patients (>age 45) in Ontario, Canada was conducted. The primary exposure was pre-operative echocardiography (between hospital admission and surgery). Patients receiving preoperative echocardiography were matched to those without using a propensity score incorporating patient demographic information, comorbidity status, and provider information. Mortality rates, surgical wait times, post-operative length of stay (LOS), and medical costs (expressed as 2013$ CAN) up to one year post-operatively were assessed after matching.

There were 2354 (∼5.6%) of 42,230 eligible hip fracture patients that received preoperative echocardiograghy during the study period. After successfully matching 2298 (∼97.6%) patients, echocardiography was associated with significant increases in mortality at 90 days (20.1% vs. 16.8%, p=0.004) and one year (32.9% vs. 27.8%, p < 0 .001), but not 30-days (11.4% vs. 9.8%, p=0.084). Patients with echocardiography also had an increased (mean ± SD) delay (in hours) from presentation to surgery (68.80 ± 44.23 hours vs. 39.69 ± 27.09 hours, p < 0 .001) and only 38.1% of patients had surgery within 48 hours. Total LOS (in days) (mean 19.49 ± 25.39 days vs. 15.94 ± 22.48 days, p < 0 .001) and total healthcare costs at one year (mean: $51,714.69 ± 54,675.28 vs. $41,861.47 ± 50,854.12, p < 0 .001) were also increased. There was wide variability in echocardiography ordering practice in Ontario, with a range of 0% to 22.97% of hip fracture patients undergoing preoperative echocardiography at different hospital sites.

Preoperative echocardiography for hip fracture patients is associated with increased postoperative mortality. It is also associated with increased surgical delay, post-operative LOS, and total health care costs at one year. Echocardiography should be considered an urgent test when ordered to prevent additional surgical delay, and further research is necessary to clarify indications for this common preoperative investigation.

Although wait-times for hip fracture surgery have been linked to mortality and are being used as quality-of-care indicators worldwide, controversy exists about the duration of the wait that leads to complications. Our objective was to use new population-based wait-time data to emprically derive an optimal time window in which to conduct hip fracture surgery before the risk of complications increases.

We used health administrative data from Ontario, Canada to identify hip fracture patients between 2009 and 2014. The main exposure was the time from hospital arrival to surgery (in hours). The primary outcome was mortality within 30 days. Secondary outcomes included a composite of mortality or other medical complications (MI, DVT, PE, and pneumonia) also within 30 days. Risk-adjusted cubic splines modeled the probability of each complication according to wait-time. The inflection point (in hours) when complications began to increase was used to define ‘early’ and ‘delayed’ surgery. To evaluate the robustness of this definition, outcomes amongst propensity-score matched early and delayed patients were compared using percent absolute risk differences (% ARDs, with 95% confidence intervals [CIs]).

There were 42,230 patients who met entry criteria. Their mean age was 80.1 (±10.7) and the majority were female (70.5%). The risk of complications modeled by cubic splines consistently increased when wait-times were greater than 24 hours, irrespective of the complication considered. Compared to 13,731 propensity-score matched patients who received surgery earlier, 13,731 patients receiving surgery after 24 hours had a significantly higher risk of 30-day mortality (N=898 versus N=790, % ARD 0.79 [95% CI 0.23 to 1.35], p = .006) and the composite outcome (N=1,680 versus N=1,383, % ARD 2.16 [95% CI 1.43 to 2.89], p < .001). Overall, there were 14,174 patients (33.6%) who received surgery within 24 hours and 28,056 patients (66.4%) who received surgery after 24 hours.

Increased wait-time was associated with a greater risk for 30-day mortality and other complications. The finding that a wait-time of 24 hours represents a threshold defining higher risk may inform existing hip fracture guidelines. Since two-thirds of patients did not receive surgery within this timeframe, performance improvement efforts that reduce wait-times are warranted.

Purpose

The effects of Acetabular Rim Osteophytes (ARO) in Total Hip Arthroplasty (THA), has not been quantified. During THA their presence and location is variable, and the effect on post-operative Range of Motion (ROM) is unknown. The purpose of this study was to evaluate the ROM of a modern hip implant in five cadaver models utilizing computerized virtual surgery, and to analyze the effect of AROs given their location on the acetabulum, and position of the prosthesis during motion.