For patients with arthritis, knee replacement offers the opportunity to regain functional mobility, reduce pain and improve quality of life. Recent data presented at the annual meeting of the American Academy of Orthopedic Surgeons (AAOS) suggest that the benefits of knee replacement may also extend to the prevention and management of cardiovascular disease in patients with moderate-to-severe osteoarthritis (OA). For patients with rheumatoid arthritis (RA) with severely arthritic knees, another study showed that same-day bilateral knee replacement is safe in selected patients.
Cardiovascular Protection of Joint Replacement in Osteoarthritic Patients
Bheeshma Ravi, MD, PhD, a physician in the Division of Orthopaedic Surgery at the University of Toronto, Ontario, Canada, reported on outcomes of a study that showed a significant reduction in the risk of subsequent cardiovascular events in people who underwent total joint replacement therapy for moderate-to-severe OA of the knee or hip.
In the study, 2,200 adults with hip and knee OA age 55 or older at the time of study recruitment (between 1996 and 1998) were followed prospectively until 2011 or death. Investigators used a propensity landmark analysis to compare the rates of serious cardiac event or death (composite outcome) and survival between people who received primary total joint athroplasty (TJA) and those who did not during the exposure period of seven years following initial assessment.
Based on a comparison of a propensity-score matched cohort of 162 matched pairs of patients with moderate-to-severe arthritis, the study found that the matched patients who underwent a TJA during the exposure period were 40% less likely to experience a serious cardiovascular event (e.g., heart attack, stroke or emergent coronary revascularization) or death compared with those who did not undergo TJA (Hazard Ratio [HR] of 0.63 [95% CI, 0.49–0.82]; P=0.0005).
Within seven years of exposure, the absolute risk reduction (of serious cardiac event or death) was 13.6% (95% CI, 3.3–23.9) and the number needed to treat was 8 (95% CI, 4–30).
According to Dr. Ravi, the cardioprotective benefit of a primary TJA is most likely due to the increased capacity for physical activity in the patients who underwent TJA. “It’s important that clinicians advise patients to use the opportunity for pain-free motion and improved function that come with arthroplasty,” he says.
However, he reiterates the need to also talk to patients about the real risks for postoperative complications after undergoing a TJA, including postoperative myocardial infarction, infection and the need for early revision.
Dr. Ravi emphasizes that the findings of the study remained consistent in various sensitivity analyses conducted in the study. He also emphasizes that, despite the small sample size that limited the ability to stratify the study by age or gender, the results of a subgroup analysis performed in persons with at least one risk factor for cardiovascular disease (other than OA) were consistent with the results of the main analysis.
Commenting on the study, Elaine Husni, MD, MPH, director of the Arthritis & Musculoskeletal Center, Cleveland Clinic, Cleveland, said the findings of the study provide a good message to patients with OA who need a TJA that there may be a possible added value to the surgery associated with reduced cardiovascular morbidity. However, she cautions that as a population-based retrospective review, only associations can be made based on the data.
“I am not sure this changes my clinical practice in terms of a decision to have surgery, which is still based on the severity of the OA disease, patient symptoms and functional ability,” she says.
As we become more sophisticated in total joint arthroplasty, our patients with RA may, if appropriately screened, benefit from same-day bilateral total joint surgeries similar to patients with OA.
Same-Day Bilateral Knee Replacement in Patients with RA
In a second study, investigators from the Hospital for Special Surgery in New York found that patients with RA who underwent same-day bilateral knee replacement had no significant differences in minor or major complications or 30-day mortality compared with patients with OA who underwent the same procedure.
“What the study showed is that in carefully selected, well-managed patients with rheumatoid arthritis, we can successfully do bilateral knee replacements,” says Mark P. Figgie, MD, chief of the Surgical Arthritis Service, Allan E. Inglis, MD Chair in Surgical Arthritis, Hospital for Special Surgery, New York, adding that these patients did relatively well even though they had a slightly higher rate of comorbidities than the patients with OA.
In the retrospective study, Dr. Figgie and colleagues compared 30-day mortality rates of in-hospital complications and risk for major morbidity or mortality between 240 patients with RA and 3,680 patients with OA who underwent same-day bilateral total knee arthroplasty between 1998 and 2011 at their high-volume institution. Compared with the patients with OA, more of the RA patients were younger, were female and had a higher rate of overall comorbidities.
The study found no difference in 30-day mortality between patients with RA and those with OA (5.8 vs. 5.4 days, P=0.007), nor in rates of procedure-related complications (2.2% vs. 1.7%, P=0.644) that were major (6.2% vs. 5.2%, P=0.463) or minor (23.7% vs. 26.6%, P=0.327).
Compared with patients with OA, patients with RA were more likely to have acute anemia after surgery (8.1% vs. 17.1%, P<0.0001) and need blood transfusions (76.5% vs. 84.2%, P=0.008); however, there was no difference between the two groups in transfer to an intensive care unit (0.7% vs. 0.8%, P=0.2) and rehabilitation (72% vs. 77%, P=0.2).
According to Dr. Figgie, the similar morbidity and mortality rates between the two groups were somewhat surprising because he and his colleagues anticipated that the RA patients would not do as well.
Importantly, he says, the RA patients selected to undergo bilateral knee replacement in the study underwent the same medical criteria used to assess the eligibility for this procedure in patients with OA. These criteria include age (procedure is not even considered in patients older than 80 years), screening for cardiovascular issues and uncontrolled diabetes.
Because patients with RA often present with complex medical and orthopedic issues, same-day bilateral knee replacement can be challenging for surgeons. Dr. Figgie emphasized that the study shows this procedure is safe in patients with RA, particularly when done in high-volume institutions that provide comprehensive care for the RA patients.
Recent data, he says, indicate that surgeons who have a high volume of RA patients tend to have better outcomes with joint replacement in these patients compared to surgeons who do a high volume of joint replacements but who do not treat many RA patients.1
For Dr. Husni, the study highlights that RA patients are most likely benefiting from the advances of RA treatment that permit more stable disease and subsequently may put them less at risk if they do need surgery. “This is promising news,” she said, “that as we become more sophisticated in total joint arthroplasty, our patients with RA may, if appropriately screened, benefit from same-day bilateral total joint surgeries similar to patients with osteoarthritis.”
Mary Beth Nierengarten is a freelance medical journalist based in St. Paul, Minn.
