Medicare claims data reveal increased risk of VTE following upper extremity arthroplasty
National rates of symptomatic venous thromboembolism after upper extremity arthroplasty were more than double than what has previously been acknowledged, according to a review of national Medicare claims from 2005 to 2007.
The incidence of venous thromboembolism (VTE) in the two calendar quarters following upper extremity arthroplasty was comparable to total hip arthroplasty. Specifically, the risk for pulmonary embolism (PE) was 6.7 per 1,000 patients for total shoulder arthroplasty compared to 8.7 per 1,000 patients in the hip.
These rates are slightly lower than, but similar to, lower extremity arthroplasty, said lead author Judd S. Day, PhD, a senior scientist at engineering and scientific consulting firm Exponent, Inc., and a part-time researcher for the School of Biomedical Engineering, Science and Health Systems at Drexel University in Philadelphia. However, we believe that rates of routine prophylaxis during upper extremity arthroplasty are lower than in the lower extremity population. Aggressive prophylaxis of this population may present with increased adverse effects, such as bleeds, and thus should be considered very carefully. Physicians should use their clinical judgment for prophylaxis and judge the patients own risk factors and clinical history.
Although VTE after lower extremity arthroplasty is well known and is addressed during training for lower extremity surgeons, most of the information available for upper extremity was purely anecdotal, Day told Orthopedics Today. Our ultimate question, which is not fully addressed by the current study is: What level of prophylaxis, considering the associated risk of bleeds, is appropriate for upper extremity arthroplasty?
Results were presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) in New Orleans. The volume of upper extremity arthroplasty is so low in comparison to lower extremity arthroplasty that it has been difficult to obtain a large enough sample, Day said. Our use of the Medicare database allowed us to follow patients in a longitudinal manner. This gave us the potential to follow them after discharge from the index procedures.
The index of suspicion has been relatively low because of the presumed relationship between the mechanical manipulation of the leg in lower extremity arthroplasty and deep vein thrombosis (DVT).
One of the interesting aspects of DVT and PE following upper extremity arthroplasty is the relatively frequent occurrence of lower extremity DVT, he said.
Day also pointed out that study results indicate that the incidence of VTE is certainly great enough to warrant the use of conservative measures. Our collaborating surgeons suggest the routine use of mechanical prophylaxis, starting in the operating room, as well as minimization of operative time and early mobilization of patients. He also noted that, Although its efficacy has not been fully characterized in this application, the use of aspirin may be appropriate.
Chemical prophylaxis should also be considered carefully. The use of more aggressive prophylaxis would depend on the assessment of the potential risk factors for the specific patient. However, further investigation is warranted before recommending full anticoagulation for upper extremity arthroplasty.
Although study data show that current rates of VTE are comparable for upper and lower extremity arthroplasty, we believe that the lower extremity patients were treated with chemical and mechanical prophylaxis, as this was the standard of care during the period of data collection, Day said. But chemical prophylaxis has not been and is still not the standard of care in upper extremity arthroplasty. This is clearly a factor that should be taken into consideration when interpreting our results.
The authors are currently refining their inclusion/exclusion criteria in order to estimate the number of false positives identified as VTE incidents. Because we are reporting comparative rates between upper and lower extremity arthroplasty, we expect this to affect the total incidence rates, but not the comparative rates between upper and lower extremity, Day said.
The study was sponsored by an Orthopaedic Research and Education Foundation (OREF)/American Shoulder and Elbow Surgeons (ASES) Rockwood Grant. by Bob Kronemyer
- Day JS, Lau E, Williams Jr. GR, et al. Increased risk of venous thromboembolism after upper extremity arthroplasty. Paper 059. Presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons. March 9-13. New Orleans.
- Judd S. Day, PhD, 3401 Market St., Suite 300, Philadelphia, PA, 19146; 215-594-8834; e-mail: email@example.com. He receives institutional or research support from Stryker and Zimmer.