Prior to TJR, clinical cardiovascular risk assessment is typically limited by severe exercise restrictions. Noninvasive pharmacological cardiovascular stress tests may predict major perioperative cardiovascular events in patients undergoing orthopaedic surgery. We undertook a pilot study to inform the feasibility of a large prospective cohort study. Patients were eligible if they were aged >
forty-five, undergoing elective TJR, and had known atherosclerotic disease or risk factors for atherosclerotic disease. We recruited patients at the Hamilton Health Sciences, Henderson Hospital. Prior to surgery patients underwent dipyridamole stress perfusion imaging and dobutamine stress echocardiography. For both tests the interpreters evaluated seventeen myocardial segments and were blinded to information about patients’ clinical risk factors. The attending surgeons and research personnel following patients after surgery were blinded to results of the noninvasive pharmacological cardiovascular stress tests. All patients had an ECG performed and troponin T drawn six to twelve hours postoperatively and on the first, second and third days after surgery. Starting in November 2005 we recruited thirty patients over six months; seventeen (57%) patients were male, twenty-one (70%) underwent TKA, and nine (30%) underwent THA. The length of surgery was seventy-two (SD 38) minutes and the length of hospital stay was five (SD 3) days. We successfully followed all patients to thirty days after surgery. Three patients (10%; 95% CI, 3–26%) suffered a perioperative myocardial infarction. Twenty nine patients underwent dipyridamole stress perfusion imaging prior to surgery; a reversible defect involving 30–50% of the myocardium increased the likelihood of a perioperative myocardial infarction (likelihood ratio [LR] 4.0; 95% CI, 1.2–13.3). Twenty-six patients underwent dobutamine stress echo-cardiography; a reversible defect increased the likelihood of a perioperative myocardial infarction (LR 4.0; 95% CI, 0.7–22.9). This pilot study demonstrates the need for, and feasibility of, a large prospective cohort study to determine if preoperative noninvasive pharmacological cardiovascular stress testing has additional predictive value, beyond clinical variables, for the occurrence of myocardial infarction in patients undergoing major hip and knee surgery.
In a meta-analysis of fourteen trials (N=1901 patients) in patients with displaced hip fractures, we identified significant reductions in the risk of revision surgery with internal fixation compared to arthroplasty. A trend towards increased mortality with arthroplasty was identified. The purpose of this study was to determine the effect of arthroplasty (hemi-arthroplasty, bipolar arthroplasty and total hip arthroplasty) in comparison to internal fixation for displaced femoral neck fractures on rates of mortality and revision surgery Arthroplasty for displaced femoral neck fractures, in comparison to internal fixation, significantly reduces the risk of revision surgery at the cost of greater infection rates, blood loss and operative time, and a possible increase in early mortality. Over 220,000 fractures of hip occur per year in North America representing an annual seven billion dollar cost to the health care system. Current evidence suggests internal fixation may reduce mortality risk at the consequence of increased revision rates. A large trial is needed to resolve this issue. We searched computerized databases (MEDLINE, COCHRANE and SCISEARCH) for published clinical studies from 1969–2002 and identified additional studies through hand searches of major orthopaedic journals, bibliographies of major orthopaedic texts and personal files. We found a non-significant trend toward an increase in the relative risk of dying with arthroplasty when compared to internal fixation (relative risk=1.27, 95% confidence interval, 0.84–1.92, p = 0.25; homogeneity p= 0.45). Arthroplasty appeared to increase the risk of dying when compared to pin and plate, but not in comparison to internal fixation using screws (relative risk= 1.75 vs 0.86, respectively, p<
0.05). Fourteen trials provided data on revision surgery (n=1901 patients). The relative risk of revision surgery with arthroplasty was 0.23 (95% confidence interval, 0.13–0.42, p = 0.0003, homogeneity p = <
0.01).