Our next speaker will be from the Stedman Clinic in Vail, Colorado. Revision rate following primary hip arthroscopy in patients given prophylactic oral Lursartan for the prevention of post-surgical fibrosis versus no Lursartan. Good morning, everyone. Thank you for the opportunity to present this research. My name is Chuck Hsu. I'll be presenting on behalf of Dr. Philippon. I have no disclosures. As we all know, over the last several decades, there's been a significant rise in the number of primary hip arthroscopy procedures performed both in the U.S. and abroad. Unfortunately, this has also been paralleled by a similar rise in the number of revision cases. In a recent large 2021 study of over 15,000 patients, found a 19% revision procedure rate with a 15.1% undergoing a revision hip arthroscopy. The most common indications for revision surgery include labral injuries or insufficiency, residual bony deformities, as well as adhesions. And specifically for adhesions, these were present in 100% revision cases at the Stedman Clinic from 2005 to 2009. So while the deposition of extracellular matrix and collagen is part of the normal healing response, in excess, this can lead to fibrosis and scar or adhesion formation. And this becomes problematic when the scar tissue attaches tissues that would normally not be connected. And in the setting of hip arthroscopy, this most commonly occurs between the iliopsoas tendon and the capsule or between the capsule and the labrum. And this can lead to pain, persistent synovitis, as well as disruption of the hip fluid seal. And while the exact pathophysiology of fibrosis remains incompletely understood, numerous basic science studies have shown an important role of TGF-beta-1 and the SMAD signaling pathway in initiating fibrosis through stimulation of fibroblast proliferation and collagen deposition. Numerous medications have been shown to be capable of inhibiting the TGF-beta pathway with decreases in fibrosis, however, have been shown to have significant and unacceptable clinical side effects. However, more recently, angiotensin II receptor antagonists, or ARBs, have also been shown to modulate TGF-beta and reduce fibrosis with a less severe side effect profile. And today, we'll be focused on Losartan, which is an FDA-approved medication long used to treat hypertension. And so seminal work from Dr. Freddie Fu and Dr. Johnny Huard's lab have demonstrated the ability of Losartan to decrease fibrosis and improve functional muscle recovery in several different small animal models of muscle injury. And so based on this promising basic science data, the senior author, Dr. Philippon, in December of 2015 began adding Losartan to all of his postoperative protocols. And this was given at a dose of 12.5 milligrams twice daily for two to six weeks postoperatively. And otherwise, there was no significant change to postoperative medications or rehab. And so given this change in practice, we were curious to know whether this addition of Losartan would have any significant impact on postoperative outcomes. And we hypothesized that patients treated with Losartan would have lower rates of reoperation and postoperative fibrosis. To evaluate this, we performed a retrospective review of 917 cases between 2012 and 2017 who underwent primary hip arthroscopy with labral repair, ephemeral and acetabular osteoplasty by a single surgeon. Exclusion criteria included age less than 18, 2 millimeters or less of joint space, and patients who underwent a concomitant microfracture or reconstructive procedure. Minimum two-year follow-up was obtained on 677 patients, of which 404 were not treated with Losartan, and 273 who received Losartan postoperatively. Although there were no gender differences between groups, the group treated without Losartan was slightly younger and did have longer follow-up just given when the Losartan treatment was initiated. We found that patients not taking Losartan had a 2.1-fold increased odds for requiring a second surgery with a 10% revision rate compared to 5% in the Losartan-treated group. And specifically for revision hip arthroscopy, we found that patients not taking Losartan had a 5.1-fold increased odds for requiring a revision hip arthroscopy. And all of these revisions included a license of adhesions. We did not find any significant difference in the rate of conversion to total hip arthroplasty between the groups, although overall patients requiring total hip arthroplasty were significantly older than those who did not convert to total hip arthroplasty. Furthermore, we did not observe any significant difference in patient-reported outcomes between patients treated with or without Losartan. So in conclusion, the incidence of revision surgery following primary hip arthroscopy did appear to be significantly lower in patients who received Losartan as part of their postoperative protocol. Reduction in revision hip surgery can improve patient outcomes and reduce healthcare costs. And the antifibrotic effect of Losartan may have other applications in orthopedic surgery. Thank you.

Chuck Hsu

Stedman Clinic

Losartan

primary hip arthroscopy

fibrosis and scar formation