Thromboembolic events lower in shoulder than THR and THA

But a larger percentage of shoulder arthroplasty-related events involve PE. Prophylaxis may reduce DVT, PE frequency.

CHICAGO — Researchers have identified the prevalence and potential risk factors associated with thromboembolic events following shoulder arthroplasty.

Robert G. Marx, MD, and colleagues at the Hospital for Special Surgery in New York, reviewed the records of nearly 14,000 total shoulder and hemi-arthroplasty patients. They found a deep vein thrombosis (DVT) rate of 5 per 1000 procedures and a pulmonary embolism (PE) rate of 2.3 per 1000 procedures. Patients admitted for trauma, who had an older age or a previous cancer diagnosis had a higher risk for such events following surgery.

The researchers also compared the frequency of thromboembolic events among shoulder arthroplasty patients to the frequency among total hip and knee patients.

“While the frequency of DVT is about three- to five-times lower among total shoulder and hemi-arthroplasty patients than in total hip and total knee patients, the frequency of PE was just 2.5-times lower,” said Marx, who presented the study results here at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting.

Marx cautioned that the study included patients admitted between 1985 and 2003. Therefore the findings may not reflect the effects of current prophylaxis measures. “It should also be noted that during the time period of this study, use of DVT and PE prophylaxis was routine among the total hips and knees, but not among the shoulders,” he said.

For the study, Marx and colleagues gathered information on over 300,000 arthroplasty patients from the New York State Department of Health’s State-wide Planning and Research Cooperative System (SPARCS) database. They then reviewed the records of patients treated with the following procedures: total shoulder arthroplasty (TSA), shoulder hemi-arthroplasty (SHA), total knee arthroplasty (TKA) or total hip arthroplasty (THA). The presence or absence of a specific code number indicated the occurrence of thromboembolic events (ie, DVT or PE).

Among TSA and SHA patients, the researchers identified 69 instances of DVT and 32 instances of PE.

Overall, shoulder patients had a DVT rate of 5 per 1000 procedures — significantly lower than THA and TKA patients. In comparison, THA patients had a DVT rate of 15.7 per 1000 and TKA patients had a rate of 26.9 per 1000.

Additionally, shoulder patients had a lower incidence of PE — 2.3 per 1000 procedures vs. 4.2 per 1000 among THA patients and 4.4 per 1000 among TKA patients, according to the study. However, “The ratio of PE to DVT in shoulder patients was higher than in patients who had THA or TKA ...,” the authors noted in the abstract.

“Although the absolute rates of thromboembolic complications were lower in shoulder procedures ... a larger percentage of these were PE. Perioperative antithrombotic prophylaxis may reduce the frequency of DVT and PE among shoulder arthroplasty patients, particularly among higher risk groups,” they said.

Marx added that the study has limitations. The research relied on the accuracy of information entered into the database. Additionally, records contained “limited information about the location of the thrombus or the use of prophylaxis to prevent DVT or PE,” he said.

For more information:
Marx RG, Lyman S, Sherman S, et al. Prevalence and risk factors for symptomatic thromboembolic events following shoulder arthroplasty. #273. Presented at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting. March 22-26, 2006. Chicago.