New CPG Addresses Hip Osteoarthritis and THA

At the 2017 AAOS Annual Meeting in San Diego, the AAOS approved the release of a Clinical Practice Guideline (CPG) on Management of Osteoarthritis (OA) of the Hip. The guideline includes four recommendations classified as "strong," being derived from evidence from two or more "high-quality" studies with consistent findings for recommending for or against an intervention, and eight classified as "moderate."

Among the strong recommendations are those endorsing use of presurgical treatments to ease pain and improve mobility, including intra-articular corticosteroid injections, physical therapy, and nonnarcotic medications—specifically, NSAIDS.

The CPG also states that the evidence does not support the use of intra-articular hyaluronic acid because it does not perform better than placebo for function, stiffness, and pain.

According to the CPG, when addressing obesity as a risk factor, moderate evidence indicates that obese patients with symptomatic OA of the hip, compared with non-obese patients, may achieve worse outcome scores but demonstrate a similar level of patient satisfaction and relative improvement in pain and function after total hip arthroplasty (THA). Limited-strength evidence supports that obese patients undergoing THA have increased incidence of postoperative dislocation, superficial wound infection, and blood loss following the procedure.


Intraoperative photograph showing retractor placement for acetabular exposure in the posterior approach to the left hip. The CPG on Osteoarthritis of the Hip states that moderate evidence indicates no clinically significant differences in outcomes related to the surgical approach used.(Reproduced from Vail TP, Berliner JL, Horst PK: Total hip arthroplasty: The modern approach, in Lieberman JR, Berry DJ, EDs: Advanced Reconstruction Hip 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2017, pp 21-32.)

The CPG panel found limited evidence to support the position that patients who use tobacco products are at an increased risk for complications after THA. Age was moderately associated with lower function and quality of life outcomes, while mental health disorders (depression, anxiety, and psychosis) were linked with decreased function, pain relief, and quality of life following surgery.

Robert H. Quinn, MD, AAOS Appropriate Use Criteria (AUC) section leader on the Committee on Evidence-Based Quality and Value and the guidelines oversight chair, said that some of the recommendations, such as those addressing obesity and tobacco use, may challenge preconceptions among some surgeons, but that as with previous CPGs, the writing panel sought to let the evidence dictate the recommendations.

"We had an extraordinary group and a process that investigated some controversial areas in the treatment of OA of the hip, and I think we can be satisfied with the outcome," Dr. Quinn said. "There is nothing extraordinarily surprising, but the findings are reassuring that there isw a strong place for THA in the treatment of advanced OA of the hip. People in different categories, including potentially compromised categories, can still benefit from these procedures, albeit with some risk but perhaps less than previously perceived in some cases. Although we suspected that age, tobacco, and mental health are risk factors, [patients with these risk factors] are still reasonable candidates to consider for a treatment that we know is very effective. Yes, these things are risk factors, but these patients can benefit from these procedures. Use of risk assessment tools is important.

We have shown with moderate evidence that these tools can be very helpful in making these decisions."

"We are enthusiastic about the completion of this CPG, as it complements the existing CPGs released by the AAOS," said Gregory Polkowski, MD, co-chair for the Guideline Work Group along with Norman Johanson, MD. "The strongest recommendations from the work group supported the use of intra-articular corticosteroids, physical therapy, and nonnarcotic pharmacologic management as conservative treatments for patients with hip OA prior to total hip replacement surgery, while we recommended against the use of intra-articular hyaluronic acid. While the data also supported many moderate and limited strength recommendations for topics related to increased surgical risk around hip replacement surgery, and while risk mitigation around elective arthroplasty surgery is an important topic in today's healthcare environment, the work group urges the interpretation of these recommendations in light of the extent of their individual evidence. These topics were included in this CPG to establish current levels of evidence and to highlight that future research needs to be conducted in these areas to better determine specifically how preoperative risk modification may affect the outcome of total hip arthroplasty surgery."

The obesity question
In regard to obesity, which can be seen as a disqualifying factor for some patients, Dr. Quinn said, "The existing evidence does not necessarily support that moderate obesity, as an independent risk factor, is a relative contraindication to surgery." Differences of opinion over what degree of obesity constitutes a prohibitive risk on its own can further cloud the issue.

Studies of obese patients and THA, Dr. Quinn said, show "that it is true that patients aren't as satisfied with the result, and there is at least some higher rate of complications. But they also start at a lower point of happiness to begin with, so the delta might even be greater than in non-obese patients."

The guideline's recommendation against the use of intra-articular hyaluronic acid because strong evidence shows that it "does not perform better than placebo for function, stiffness, and pain" in patients with hip OA hews to the Academy's previous guideline in regard to such injections for knee osteoarthritis. That recommendation drew opposition in some quarters but, Dr. Quinn said, "In spite of much resistance to the Academy position, the evidence has continued to support our finding. The Academy has consistently shown that high-level evidence shows that this expensive and somewhat invasive technique really does not make a difference. We have been consistent in our message, and the evidence has been consistent."

He noted that the CPG does lend support to the use of intra-articular corticosteroids. "Corticosteroids are inexpensive and are a little bit invasive, but they work. So they are cost-effective. So we are not saying that injectables don't work. There is one that works well and it's safe and economical."

Two recommendations backed by moderate evidence address surgical considerations in THA. One is in support of use of intravenous or topical tranexamic acid to reduce blood loss. The other states that no clinically significant differences were seen in patient-oriented outcomes related to the surgical approach.

The CPG was endorsed by the Pediatric Orthopaedic Society of North America.

Terry Stanton is the senior science writer for AAOS Now. He can be reached at tstanton@aaos.org

Sheryl Cash is manager, media relations, for AAOS Public and Media Relations. She can be reached at scash@aaos.org

Additional Information:
Clinical Practice Guideline (CPG) on Management of Osteoarthritis (OA) of the Hip

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