Outpatient TKA Riskier; AAOS Hip OA Appropriate Use Criteria; Bisphosphonates for Knee OA—NOT Effective!

Outpatient TKA Associated with Higher Risks

Having total knee arthroplasty (TKA) on an outpatient basis may require another look, says a new study from the University of California, Los Angeles (UCLA).

Researchers found that outpatient TKA was associated with a higher risk of complications. The article, “Outpatient Total Knee Arthroplasty Is Associated with Higher Risk of Perioperative Complications,” appears in the December 6, 2017 edition of The Journal of Bone and Joint Surgery.

Armin Arshi, M.D., orthopedic resident at the David Geffen School of Medicine at UCLA and co-author on the study, told OTW, “Our field has made great efforts to decrease hospital length of stay following joint replacement as a mechanism to improve patient satisfaction and decrease costs at the population-level. With this shift to outpatient and short-stay arthroplasty, we were interested in knowing how this fared in terms of complication rate and patient selection.”

“We believe that, while it has its well-described limitations, ‘big data’ sources can be particularly helpful in asking questions such as these and understanding trends and outcomes in a large population that would be difficult to achieve from a single institution.”

The authors wrote, “Cohorts of 4,391 patients who underwent outpatient TKA and 128,951 patients who underwent inpatient TKA were identified. The median age was in the 70 to 74-year age group in both cohorts.”

“The incident of outpatient TKA increased across the study period. After adjustment for age, sex, and CCI [Charleston Comorbidity Index], outpatient TKAs were found to be more likely followed by tibial and/or femoral component revision due to a non-infectious cause, explantation of the prosthesis, irrigation and debridement, and stiffness requiring manipulation under anesthesia within 1 year. Outpatient TKA was also more frequently associated with postoperative deep vein thrombosis and acute renal failure.”

Dr. Arshi commented to OTW, “With the emerging literature, we were not surprised to find that the frequency of outpatient TKA is increasing in the United States. We also found that outpatient TKA was associated with a slightly higher adjusted risk (anywhere from 20-65% higher) of postoperative complications including surgical site infection, deep vein thrombosis, revision arthroplasty, and postoperative stiffness compared to standard TKA with an inpatient hospital course of at least 24 hours.”

“Our main recommendation is that surgeons and healthcare administrators be aware of these slight increases in risk. While we are aware that they are small in an absolute sense and may be of questionable clinical significance to the individual provider, we believe it is an important factor for surgeons to be aware of when selecting who is appropriate for outpatient knee replacement and for preoperative counseling and preparation.”

“We believe that further work in identifying which specific categories of patients (with respect to age or medical comorbidities) may be most susceptible to these higher complication rates is critical as outpatient arthroplasty continues to expand and evolve.”

AAOS Approves Appropriate Use Criteria for Hip OA

After much consideration, the American Academy of Orthopaedic Surgeons (AAOS) Board of Directors has approved new Appropriate Use Criteria (AUC) for Management of Osteoarthritis of the Hip.

As AAOS wrote in its December 12, 2017 news release, “The AAOS AUCs provide clinicians with algorithms on how to optimally treat an orthopaedic injury or condition, including hypothetical scenarios and possible treatments, ranked for appropriateness based on the latest research and clinical expertise and experience.”

“The new AUC supports the Clinical Practice Guideline, ‘Management of Osteoarthritis of the Hip’ that strongly recommends: The use of pre-surgical treatments to ease pain and improve mobility, including corticosteroid injections, physical therapy and non-narcotic medication (specifically acetaminophen, non-steroidal anti-inflammatory drugs or tramadol) for pain. Both anterior and posterior approaches for total hip replacement surgery.”

In addition, the new criteria highlight when “hip replacement may be appropriate even when patients have modifiable risk factors, such as obesity, mental health disorders, smoking and diabetes,” said Robert H. Quinn, M.D., AAOS AUC section leader on the Committee on Evidence-Based Quality and Value.

For example, “some patients, who have worked closely with their medical team to best mitigate these risk factors, might be considered on an individual basis” for surgery, said Dr. Quinn. “In these instances, the doctor and patient must weigh the benefits and risks of surgery. At the end of the day it’s one surgeon and one patient, and hopefully both are considering the optimal treatment, based on the patient’s particular condition and diagnosis.”

Dr. Quinn commented to OTW, “The biggest challenge is in the organization and first steps. We need to insure that we create a balanced panel of all relevant disciplines involved with the treatment of hip OA and insure that there is a high level of expertise while minimizing perceived conflicts of interest in an effort to create a trusted final product with broad buy-in. The next biggest challenge is to insure that the correct framework is established in the beginning, including the questions to be asked and assumptions to be made.”

Asked how their implementation will be monitored, Dr. Quinn told OTW, “To date no formal process exists. We are trying to develop monitoring, recording, and reporting processes by working directly with electronic health record companies and payers. We are also hopeful that new registry initiatives will facilitate the monitoring and outcome processes.

Bisphosphonates for Knee OA—NOT Effective

Bisphosphonates for knee OA? Forget about it, says new research from Tufts University School of Medicine in Boston. The study, “Are bisphosphonates efficacious in knee osteoarthritis? A meta-analysis of randomized controlled trials,” appears in the December 5, 2017 edition of Osteoarthritis and Cartilage.

The study analyzed seven randomized controlled trials (RCTs) (3,013 patients), with the majority of patients (2767) receiving oral risedronate.

Co-author Elizaveta Vaysbrot, M.D., M.S., with the department of rheumatology at Tufts, commented to OTW, “Our area of interest in research always involved the efficacy and safety of treatments used (or proposed to be used) in osteoarthritis (OA). This particular topic of using bisphosphonates in the treatment of OA, however, came to our close attention inadvertently as we were gathering and summarizing the body of literature for an evidence report aimed to inform knee OA treatment guidelines.”

“While performing preliminary analyses, we discovered that our results showed a lack of efficacy of bisphosphonates, whereas the previously published reviews, of which we were aware, suggested the opposite.”

“In addition, we were familiar with preclinical research showing that it was biologically plausible for these agents to have effect in OA. On the other hand, some larger clinical trials of bisphosphonates in OA did not seem to arrive to positive conclusions. Therefore, we felt compelled to investigate this topic further to see whether bisphosphonates indeed offer any benefit in OA.”

“Because pooling extremely heterogeneous studies could muddle up the conclusions (and could partly explain some results of earlier reviews), we tried our best to reduce heterogeneity in our review by selecting only randomized controlled trials = RCTs (no observational data); only trials in knee OA (no hip OA or OA of other joints); no concomitant treatments other than typical rescue medications used in RCTs; and using only placebo as a comparator (no active comparator arms).”

“In addition, we took great care to extract data in duplicate, paying particular attention to measures of variation. We knew that, for example, failure to calculate standard deviations from standard errors is a common pitfall we’ve seen in some papers, which might give appearance of statistical significance to comparisons that were not actually significant by incorrectly narrowing down margins of error of confidence intervals.”

“Finally, a few of the included studies presented important outcomes only as graphs, and we had to make sure to extract those data with highest precision possible. To do so, we used special software that helps to scale and measure any outcomes presented in graphical form.”

Raveendhara R. Bannuru M.D., Ph.D., F.A.G.E., director of the Center for Treatment Comparison and Integrative Analysis (CTCIA) at Tufts and co-author on the study, told OTW, “The most important inference here, of course, is that bisphosphonates don’t work in knee OA (and it is hard to imagine a pathophysiological mechanism allowing for these drugs to perform better in other OA locations).”

“This conclusion agrees with the results of the larger, better-quality RCTs conducted on the topic. There is still a possibility that bisphosphonates may be beneficial in some narrowly defined subsets of OA patients. However, much research is needed to figure out what describes such subsets and how to detect the predisposition of certain individuals suffering from OA to the favorable effects of bisphosphonates.”

“As of today, bisphosphonates have not been approved by the FDA for the treatment of OA. We suggest that bisphosphonates should continue to be prescribed as currently indicated—for the prevention and treatment of osteoporosis and for the treatment of some other bone diseases, such as Paget’s, as per medication package insert. Until further high-quality evidence on the efficacy of bisphosphonates in some subsets of OA patients emerges, we suggest that these agents are not to be prescribed with the sole purpose of treating OA.”

“Again, we suggest that bisphosphonates should not be used for OA, outside of scope of current indications (as prescribed in the appropriate medication package insert) at least until sufficient new and high quality research on this topic emerges.”