Patient satisfaction is an important measure of patient-centered outcomes and physician performance. Given the continued growth of the population undergoing surgical intervention for osteoarthritis (OA), and the concomitant growth in the associated direct costs, understanding what factors drive satisfaction in this population is critical. A potentially important driver not previously considered is satisfaction with pre-surgical consultation. We investigated the influence of pre-surgical consultation satisfaction on overall satisfaction following surgery for OA.

Study data are from 1263 patients who underwent surgery for hip (n=480), knee (n=597), and spine (n=186) OA at a large teaching hospital in Toronto, Canada. Before surgery, patient-reported satisfaction with information received and degree of input in decision-making during the pre-surgical consultation was assessed, along with expectations of surgery (regarding pain, activity limitation, expected time to full recovery and likelihood of complete success). Pre- and post-surgery (6 weeks, and 3, 6, and 12 months) patients reported their average pain level in the past week (0–10, 10 is worst). At each follow-up time-point, two pain variables were defined, pain improvement (minimal clinically important difference from baseline ≥2 points) and ‘acceptable’ pain (pain score ≤ 3). Patients also completed a question on satisfaction with the results of the surgery (very dissatisfied/dissatisfied/somewhat satisfied/very satisfied) at each follow-up time point. We used multilevel ordinal logistic regression to examine the influence of pre-surgery satisfaction with consultation on the trajectory of satisfaction over the year of recovery controlling for expectations of surgery, pain improvement, acceptable pain, socio-demographic factors (age, sex, and education), body mass index, comorbidity, and depressive symptoms (Hospital Anxiety and Depression Scale).

Mean age of the sample was 65.5 years, and over half (54.3%) were women. Overall, 74% and 78.9% of patients were satisfied with the information received and with the decision-making in the pre-surgical consultation, respectively, no significant differences were found by surgical joint (p=0.22). Post-surgery, levels of satisfaction varied very little over time (6 weeks: 92.5% were satisfied and 66.4% were very satisfied, 1 year: 91.1% were satisfied and 65.6% were very satisfied). Results from a model including time, surgical joint, satisfaction with consultation and control factors indicated that being satisfied with the information received in the pre-surgical consultation was associated with higher odds of being more satisfied after surgery (OR: 1.2, 95% CI: 1–1.4). Additionally, spine and knee patients were more likely to be dissatisfied than hip patients (OR: 3.2, 95% CI: 2.1–4.9 and OR: 2.5, 95% CI: 1.8–3.4 for spine and knee patients respectively). Achieving pain improvement (OR: 1.7, 95% CI: 1.3–2.4) and acceptable pain (OR: 2.5, 95% CI: 1.6–3.9) were both significantly associated with greater satisfaction. Pre-operative expectations were not significantly associated with post-surgery satisfaction.

Findings highlight the important role of pre-surgery physician-patient communication and information on post-surgery satisfaction. This points to the need to ensure organizational provisions that foster supportive and interactive relationships between surgeons and their patients to improve patients' satisfaction. Findings also highlight that early post-recovery period (i.e. <= 3 months) as a key driver of longer-term satisfaction.

In addition to mechanical stresses, an inflammatory mediated association between obesity and knee osteoarthritis (OA) is increasingly being recognised. Adipokines, such as adiponectin and leptin, have been postulated as likely mediators. Clinical and epidemiological differences in OA by race have been reported. What contributes to these differences is not well understood. In this study, we examined the profile of adipokines in knee synovial fluid (SF) and the gene expression profile of the infra-patellar fat pad (IFP) by race among patients with end-stage knee OA scheduled for knee arthroplasty.

Age, sex, weight and height (used to derive body mass index (BMI)) and race (White, Asian and Black) were elicited through self-report questionnaire prior to surgery. SF and IFP samples were collected at the time of surgery. Adipokines (adiponectin and leptin) were examined in the SF using MAGPIX Multiplex platform. IFP was profiled using Human Adipogenesis PCRArray and genes of interest were further validated via quantitative relative RT-PCR using Student's t-test. Overall differences in adiponectin and leptin concentrations were tested across race. Linear regression modeling was used to investigate the association between adiponectin and leptin concentrations (outcomes) and race (predictor; referent group: White), adjusting for age, sex and BMI.

67 patients (18 White, 33 Asian, 16 Black) were included. Mean SF adiponectin concentration was greatest in Whites (1175.05 ng/mL), followed by Blacks (868.53 ng/mL) and Asians (702.23 ng/mL) (p=0.034). The mean SF leptin concentration was highest in Blacks (44.88 ng/mL), followed by Whites (29.86 ng/mL) and Asians (20.18 ng/mL) (p=0.021). Regression analysis showed Asians had significantly lower adiponectin concentrations compared to Whites (p<0.05). However, leptin concentrations did not differ significantly by race after adjusting for covariates. Testing of the IFP, using the Adipogenesis PCRArray, showed significant higher expression of LEP gene (leptin, p=0.03) in Asians (n=4) compared to Whites (n=4).

There appears to be important racial differences in the SF adiponectin profile among individuals with end-stage knee OA. Differential gene expression in the IFP across racial groups could be a potential contributory source for the noted SF variations. Further work to determine the source and function of adipokines in knee OA pathophysiology across racial groups is warranted.

Osteoarthritis (OA) is the most common form of arthritis worldwide. It is a major cause of disability in the adult population with its prevalence expected to increase dramatically over the next 20 years. Although current therapies can alleviate symptoms and improve function in early course of the disease, OA inevitably progresses to end-stage disease requiring total joint arthroplasty. Mesenchymal stromal cells (MSCs) have emerged as a candidate cell type with great potential for intra-articular (IA) repair therapy. However, there is still a considerable lack of knowledge concerning their behaviour, biology and therapeutic effects. To start addressing this, we explored the secretory profile of bone marrow derived MSCs in early and end-stage knee OA synovial fluid (SF).

Subjects were recruited and categorised into early [Kellgren-Lawrence (KL) grade I and II, n=12] and end-stage (KL grade III and IV, n=11) knee OA groups. The SF proteome of early and end-stage OA was tested before and three days after the addition of bone marrow MSCs (16.5×10^3, single donor) using multiplex ELISA (64 cytokines) and mass spectrometry (302 proteins detected). Non parametric Wilcoxon-signed rank test for paired samples was used to compare the levels of proteins before and after addition of MSCs in early and end-stage knee OA SF. Significant differences were determined after multiple comparisons correction (FDR) with a p<0.05.

Gender distribution and BMI were not statistically different between the two cohorts (p>0.05). However, patients in early knee OA cohort were significantly younger (44.7 years, SD=7.1) than patients in the end-stage cohort (58.6 years, SD=4.4; p<0.05). In both early and end-stage knee OA, MSCs increased the levels of VEGF-A (by 320.24 pg/mL), IL-6 (by 826.78 pg/mL) and IL-8 (by 128.85 pg/mL), factors involved in angiogenesis; CXCL1/2/3 (by 103.35 pg/mL), CCL2 (by 1187.27 pg/mL), CCL3 (by 15.82 pg/mL) and CCL7 (by 10.43 pg/mL), growth factors and chemokines. However, CXCL5 (by 48.61 pg/mL) levels increased only in early knee OA, whereas PDGF-AA (by 15.36 pg/mL) and CXCL12 (by 497.19 pg/mL) levels increased only in end-stage knee OA.

This study demonstrates that bone marrow derived MSCs secrete angiogenic and chemotactic factors both in early and end-stage knee OA. More importantly, MSCs show a differential reaction between early and end-stage OA. Functional assays are required to further understand on how the therapeutic effect of MSCs is modulated when exposed to OA SF.

Recently, several high impact randomised controlled trials have been published suggesting no greater benefit from orthopaedic surgery over conservative treatment, or limited surgical intervention. These studies can have profound effects on clinical practice, leading to the abandonment of previously widely-used operations.

How do surgeons who believe these operations are beneficial over conservative treatment rationalise these findings, and justify their use with hospital administrators and health care funders who require evidence for the value and efficacy of surgical treatment?

Cite this article: Bone Joint J 2015;97-B:1456–7.

Purpose

With the advent of newer diagnostic imaging tools, the reported prevalence of acute pulmonary embolism (PE) following total hip (THA) and total knee (TKA) arthroplasty appears to be increasing. However, the true prevalence and clinical relevance of these events are unclear. Our study was designed to evaluate the results of routine multi-detector computed tomography (MDCT) in this patient population in the early postoperative period.

Purpose

Femoral nerve blockade (FNB) can provide prolonged postoperative analgesia and facilitate rehabilitation following major knee surgery while minimizing opioid-related adverse effects. However, anecdotal data have implicated FNB in post-operative falls, presumably due to a block-related reduction in quadriceps strength. Age, gender and knee replacement surgery have also been previously identified as risk factors for falls in the acute postoperative orthopaedic inpatient setting. We hypothesized that the use of FNB would be an independent predictor of an inpatient fall following total knee replacement (TKR).

Purpose

Elective ACLR is indicated for symptomatic instability of the knee. Despite being a common procedure, there are numerous surgical techniques, graft and fixation choices. Many have been directly compared in randomized trials and meta-analyses. The typical operation is arthroscopic-assisted, uses autograft tendon and screw fixation. Research in elective joint replacement surgery has demonstrated an inverse relationship between surgeon volume and revision and complication rates. How patient demographics, provider characteristics and graft/fixation choices influence ACLR revision rates has not been reported on a population level. We hypothesized that ACLR using tendon autograft and screw fixation performed by high volume surgeons will have the lowest rate of revision. In contrast, the risk of contralateral ACLR in the same cohort will be influenced only by patient factors.

Purpose

Although total knee replacement (TKR) has a high reported success rate, the pain relief and functional improvement after surgery varies. We asked what is the prevalence of patients showing no clinically significant improvement 1-year after TKR, and what are the patient level factors that may predict this outcome.

Purpose

Total knee arthroplasty (TKA) is the preferred treatment for those with end stage osteoarthritis (OA) and severe functional limitations. With the demographic transition in society, TKA is being offered to a younger patient population. Younger patients are generally more active requiring an increased range of motion, and place greater physiological demands on the prosthesis than typical older patients. The mobile bearing (MB) total knee prosthesis has theoretically been designed to meet these demands. We conducted a meta-analysis and systematic review of randomized controlled trials comparing outcomes of MB and fixed bearing (FB) TKA.

Purpose

Factors that contribute to early and late re-operation after cruciate reconstruction (CR) have not been evaluated on a population level in a public health system. After surgery patients are at risk for knee stiffness, infection or early graft failure prompting revision. Long-term, ipsilateral revision CR, contralateral CR and potentially even joint replacement may occur. Population research in total joint replacement surgery has demonstrated an inverse relationship between complication/failure rates and surgeon procedural volume. We hypothesized that in Ontario, younger patient age and lower surgeon volume would increase the risk of short and long-term re-operation after CR.

Purpose: Minimally invasive surgery (MIS) knee replacement surgery has experienced a recent surge in popularity, driven by the patient concerns of a faster recovery time and a shorter, more cosmetic scar. However the evaluation of any new medical therapy must include a detailed evaluation of both efficacy and safety outcomes. The primary objective of our meta-analysis was to compare the incidence of complications between minimally invasive(MIS) and standard total knee replacement (TKR) approaches.

Method: We reviewed randomized controlled trials comparing minimally invasive TKR to standard TKR. After testing for publication bias and heterogeneity, the data were aggregated by random-effects modeling. Our primary outcome was the number of complications. Our secondary outcomes were alignment outliers, Knee Society Function Scores, and Knee Society Knee Scores.

Results: We had a total of 9 studies evaluating our primary outcome. Average follow up time ranged from 3 to 28 months. There was no significant publication bias in our study.

The combined odds ratios for complications for the MIS group and alignment outliers were 1.58 (95% CI: 1.01 to 2.47) p< 0.05 and 0.79 (95% CI: 0.34 to 1.82) p=0.58 respectively. The standard difference in means for Knee Society scores was no different between groups.

Conclusion: The results of this meta-analysis demonstrate a statistically significant increase in complication rates with MIS TKR when compared to standard TKR. There were no significant differences in postoperative alignment or KSS at 3 months between the two groups. MIS knee surgery should be approached with caution.

Purpose: Obesity is known to be a risk factor for the incidence and progression of prevalent osteoarthritis (OA). The relationship is traditionally believed to be a mechanical effect on weight bearing joints such as the hip and knee, however studies showing a relationship between body mass index (BMI) and OA of non-weight bearing joints, such as the hand, suggest another theory. They suggest that the relationship between obesity and joint degeneration may be a systemic metabolic effect whereby visceral and sub-cutaneous truncal white adipose tissue (WAT) secrete inflammatory mediators that directly influence the pathogenesis of OA. We asked what is the relationship between adiponectin, leptin, and the A/L ratio and patient reported pain in an end stage knee OA joint population.

Method: We collected demographic data, Short Form McGill Pain scores, WOMAC pain scores, and synovial fluid (SF) samples from 60 consecutive patients with severe knee OA at the time of joint replacement surgery. Synovial fluid samples were analyzed for leptin and adiponectin using specific ELISA. Non-parametric correlations and linear regression modeling were used to identify the relationship between the adipokines and pain levels.

Results: The correlations between the individual adipokines and the pain scales were consistently less than that for the corresponding adipokine ratio. The A/L ratio correlated moderately with the MPQ-SF, (r(58) = − 0.46, p < .01) and the WOMAC pain score, (r(58) = − 0.38, p > .01). Linear regression modeling demonstrated that the A/L ratio was a significant predictor of a greater level of pain on the MPQ-SF(p=0.03, Table 3) but not the WOMAC pain scale(p=0.77, Table 4). Models were adjusted for age, gender, BMI, and medical comorbidity.

Conclusion: In conclusion, a greater A/L ratio predicted lower knee OA pain as measured by the MPQ-SF, but not on the WOMAC pain scale. This finding was above that of the individual adipokine levels alone. Some authors have suggested that leptin may have a proin-flammatory role while adiponectin an anti-inflammatory role in synovial joint diseases. Further work to elucidate these pathways may present a target for novel therapeutics in knee OA.

Purpose: Factors influencing patient willingness to undergo elective surgery are poorly understood.

Method: We prospectively evaluated patient concerns prior to surgical consultation for elective spinal, hip, knee, shoulder/elbow (S/E), or foot/ankle (F/A) conditions. Patients were surveyed for demographic data, SF 36 quality of life (QOL) scores and asked to report their greatest concern about considering surgery for their condition, as well as their willingness to undergo surgery if it was offered to them by their treating surgeon.

Results: In our prospective cohort of 743 patients, 364 (51%) were male and 293 (39 %) were evaluated for a spine condition, 74 (10 %) hip, 192 (26 %) knee, 69 (9 %) S/E, and 115 (16 %) F/A. Mean QOL scores were similar for patients across specialities. The top three greatest concerns for undergoing elective musculoskeletal surgery were potential complications (20%), effectiveness (15%) and recovery time (15%) of surgery. When categorized by specialty, concern of surgical complications was the most prevalent in spine (23%) and F/A patients (30%). However, patients were most commonly unsure of risks associated with their respective subspecialty surgery (spine – 56%; hip – 53%; knee – 44%; S/E – 48% and F/A – 33%). The majority of hip patients (89%) perceived a high success rate for hip surgery, while 65% of spine patients where unsure of the success of spine surgery. Patient willingness to undergo surgery was greatest for hip (84%), knee (78%), and S/E (82%) surgery and least for spine (68%) and F/A surgery (74%).

Conclusion: Although patient willingness to consider surgery is clearly a multifactorial decision, patient perception of surgical risk or success prior to surgical consultation are significant factors.

Purpose: MetS has been shown to be a risk factor for chronic diseases such as cardiovascular diseases (CVD), including myocardial infarction and stroke, and dementia. Moreover, the risk factors that make up the MetS (central obesity, diabetes, high blood pressure, and dyslipidemia) have also been demonstrated to have independent relationships to degenerative joint disease. The relationship between the metabolic factors and spine OA have been examined by few, however the predictive value of MetS on the incidence or prevalence of this disease has not been studied. In this study, we asked whether the prevalence of spinal OA increases with the number of MS risk factors.

Method: We reviewed data from a single surgeon, high volume, spine surgery practice between the years of 2002–2007. Demographic data including the components of the MetS risk factors were collected. Prevalent severe OA was defined as degenerative spondylolisthesis or cervical or lumbar stenosis causing neurologically based symptoms, and early OA as those with lumbar and cervical spondylosis causing axial pain only. Logistic regression modeling was used to determine the odds (adjusted for age and sex) of having severe spine OA with an increasing number of the MetS risk factors.

Results: In our cohort of 1502 patients, there were 839/1502 (55.9%) patients defined as severe spinal OA and 663/839 (44.1%) patients with early OA. Those with severe spinal OA were significantly older, with a greater percentage of females, and had a greater BMI than those with early spinal OA (p < .05). The prevalence of severe spinal OA varied across groups defined by the number of MetS risk factors: 353/748 (47.2%) in those with 0 MetS risk factors, 236/392 (60.2 %) in those with 1 MetS risk factors, 148/228 (64.9 %) in those with 2 MetS risk factors, 76/104 (73.1 %) in those with 3 MetS risk factors, and 26/30 (86.7 %) in those with all 4 MetS risk factors. The overall prevalence of MetS was 30/1502 (2.0%), 26/839 (3.1%) in the severe OA group and 4/663 (0.6%) in the early OA group.(p= .001) Logistic regression modeling showed the odds of having severe spinal OA increased with an increasing number of MetS risk factors relative to having no MetS risk factors. Those patients having defined as MetS had almost a 4 times greater odds of having severe spinal OA as compared to those with no MetS risk factors, adjusted for age and gender [OR 3.9,(1.4, 11.6), p= .01].

Conclusion: The components of MetS are more prevalent in those with severe spinal OA causing neurological symptoms compared to those with spondylosis causing axial pain. Future work should examine for an association between MetS and incident OA.

Purpose: Synovial fluid (SF) leptin has been shown to have an association with cartilage degeneration. Our objective was to examine the relationship between different measures of body habitus and SF leptin levels in an end stage knee osteoarthritis (OA) population.

Method: Sixty consecutive patients with knee OA were surveyed prior to surgery for demographic data. Body habitus was assessed with the body mass index (BMI), waist circumference (WC) and waist-hip ratio (WHR). SF and serum samples were analyzed for leptin and adiponectin using specific ELISA. Non-parametric correlations and linear regression modeling was used to identify the relationship between the measures of body habitus and SF leptin levels.

Results: Females had greater levels of leptin than males in both the serum and SF. Significant correlations were found between SF leptin levels and BMI and WC (R2 0.44 and 0.38 respectively, p< 0.05). Regression modeling showed that female gender and WC were independent predictors of a greater SF leptin level independent of age, BMI, and presence of diabetes.(p< 0.05)

Conclusion: WC may be a more accurate measure of body habitus than BMI in the relationship between the metabolic effects of adipose tissue and OA.

Purpose: Prophylactic use of antibiotic-laden bone cement (ALBC) has been proposed to decrease the incidence of deep infections. We asked if the use of antibiotic laden bone cement decreased the deep infection rate following primary total knee replacement (TKA) as compared to plain bone cement (PBC).

Method: We surveyed 1,625 consecutive patients undergoing cemented, primary knee replacement with either ALBC or PBC. Relevant covariates including age, body mass index (BMI), gender, education, and medical comorbidity were collected. Joint pain and functional status were assessed at baseline and at 1 year follow up with the respective Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores. The incidence of deep infection at 1 year follow up was recorded.

Results: There were 811 (49.9%) patients in the ALBC group and 814(50.1%) in the PBC group. There were no differences in age, gender, BMI, education or comorbidity between groups at baseline (p> 0.05). We found a deep infection rate of 3.1% in the ALBC group and 2.2% in the PBC group (p=0.27). Adjusted analysis showed that ALBC was not predictive of a lower infection rate at 1 year (p=0.84).

Conclusion: ALBC did not reduce the incidence of deep infection following primary TKA at 1 year follow up. Further studies are needed to define any high risk groups for which ALBC might be beneficial.

Purpose: Metabolic syndrome (MS) is defined as central adiposity, elevated fasting glucose, hypertension, and dyslipidemia defined as high triglyceride and low high-density lipoprotein (HDL) cholesterol. MS is associated with a systemic proinflammatory and prothrombotic state. We asked if patients with MS undergoing total knee arthroplasty (TKA) have an increased risk for symptomatic deep vein thrombosis at 3 months follow-up (DVT).

Method: 1,460 consecutive patients were reviewed from our joint registry undergoing primary, unilateral TKA between the years of 1998–2006. Demographic variables of age, gender, comorbidity, and education were retrieved. Metabolic syndrome (MS) was defined as body mass index above 30 kg/m2, diabetes, hypertension, and hypercholesterolemia. Logistic regression was used to examine the relationship of MS on the incidence of DVT.

Results: The overall incidence of symptomatic DVT was 4.4% (65/1460). Patients with MS had an increased incidence of DVT as compared to those without MS(15.5% vs 3.4%). Adjusted analysis showed that MS increased the risk of symptomatic DVT by 3.2(95% CI [1.0,15.4], p=0.04) times compared to those without MS.

Conclusion: Hospital protocols developed for prophylactic anti-coagulation following TKR should give special consideration to patients with MS.

Using meta-analysis we compared the survival and clinical outcomes of cemented and uncemented techniques in primary total knee replacement. We reviewed randomised controlled trials and observational studies comparing cemented and uncemented fixation. Our primary outcome was survival of the implant free of aseptic loosening. Our secondary outcome was joint function as measured by the Knee Society score. We identified 15 studies that met our final eligibility criteria. The combined odds ratio for failure of the implant due to aseptic loosening for the uncemented group was 4.2 (95% confidence interval (CI) 2.7 to 6.5) (p < 0.0001). Subgroup analysis of data only from randomised controlled trials showed no differences between the groups for odds of aseptic loosening (odds ratio 1.9, 95% CI 0.55 to 6.40, p = 0.314). The weighted mean difference for the Knee Society score was 0.005 (95% CI −0.26 to 0.26) (p = 0.972).

There was improved survival of the cemented compared to uncemented implants, with no statistically significant difference in the mean Knee Society score between groups for all pooled data.

Our aim was to determine the effect of delay to surgery on the time to discharge, in-hospital death, the presence of major and minor medical complications and the incidence of pressure sores in patients with a fracture of the hip. All patients admitted to Vancouver General Hospital with this injury between 1998 and 2001 inclusive were identified from our trauma registry. A review of the case notes was performed to determine the delay in time from admission to surgery, age, gender, type of fracture and medical comorbidities. A time-to-event analysis was performed for length of stay. Additionally, a Cox proportional hazards model was used to determine the effect of delay to surgery on the length of stay while controlling for other pertinent confounding factors. Using logistical regression we determined the effect of delay to surgery on in-hospital death, medical complications and the presence of pressure sores, while controlling for confounding factors.

Delay to surgery (p = 0.0255), comorbidity (p < 0.0001), age (p < 0.0001) and type of fracture (p = 0.0004) were all significant in the Cox proportional hazards model for increased time to discharge. Delay to surgery was not a significant predictor of in-hospital mortality. However, a delay of more than 24 hours was a significant predictor of a minor medical complication (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.05 to 2.22), while a delay of more than 48 hours was associated with an increased risk of a major medical complication (OR 2.21, 95% CI 1.01 to 4.34), a minor medical complication (OR 2.27, 95% CI 1.38 to 3.72) and of pressure sores (OR 2.29, 95% CI 1.19 to 4.40).

Patients with a fracture of the hip should have surgery early to lessen the time to acute-care hospital discharge and to minimise the risk of complications.

Retrospective review of four thousand two hundred and fifty-two patients undergoing TJR at a single high-volume arthroplasty centre to determine prevalence and timing of myocardial infarction (MI) following TJR. The incidence of peri-operative MI was 1.5%, with a mean of three days to time of MI. This cohort was comprised of 55% females with a mean age of seventy-five years. We found poor correlation between pre-operative risk assessment using the Modified Multifactorial Index score. Our findings suggest that there is a minimum length of stay compatible with patient safety given the inadequacy of currently available preoperative risk assessment tools.

This study was undertaken to evaluate the prevalence and timing of peri-operative myocardial infarction in patients undergoing total joint replacement (TJR).

Despite the pressure toward decreasing length of stay following TJR surgery, we suggest that there is a minimum length of stay compatible with patient safety given the inadequacy of currently available preoperative risk assessment tools.

The prevalence rate of peri-operative MI was 63/4252(1.5%), with a mean time of three days (range 0–18) to MI. Furthermore, there was a predominance of females (55%) and a mean age of seventy-five years among this cohort. We found poor correlation between pre-operative risk assessment using the Modified Multifactorial Index score.

Patients who suffered an acute MI following elective TJR surgery between April 1998 and April 2003 were abstracted from the Hospital CIHI database of four thousand two hundred and fifty-two patients. The role of preoperative risk assessment and risk reduction strategies were also evaluated.

The previously reported rate of MI is 0.3 % and 0.9% following unilateral and bilateral TJR respectively. The reported frequency of MI tends to increase with older age (> 70 yrs) and male gender. There is emerging information that these rates may be grossly under-estimated. Prosthetic arthroplasty is major surgery and regardless of the surgical technique, patients remain at risk for complications.