Thursday, September 5, 2013

Hip Cartilage Arthritis Linked to Failed Hip Impingement Surgery

This post is a bit of a mish mash on arthritis. Lots of new research has been published on femoroacetabular impingement, FAI, recently. PubMed is virtually exploding with new entries on hip impingement, FAI.  A few worth mentioning (and I might just come back with a more detailed version) touch upon the topic of why some surgeries to treat FAI fail. Failure isn’t a word patients like to hear, so here is what patients need to know.

One meta-analysis looked at 13 studies to see what the common denominators in failed FAI surgeries were.  Failure was defined as either (a) a lack of statistically significant improvement in validated measures of pain, function, or satisfaction after surgery, or, (b) revision surgery or conversion to a total hip replacement because of persistent symptoms. (1)

The meta-analysis stated that there was a consistent association between variables before surgery and clinical outcomes reported in all of the 13 studies, however there weren’t any randomized trials. Many studies even showed methodological shortfalls. Nevertheless, the meta-analysis authors were able to draw the following conclusions.

Cartilage damage or osteoarthritis that existed before the FAI surgery showed the strongest and most consistent correlation to patients moving on to a total hip replacement (arthroplasty) and with a lack of improvement in pain or function.

In addition, the greater the age at the original operation, the worse the preoperative modified Harris Hip  Score (MHHS) and the longer the symptoms had been present before the operation, the worse the outcome was after surgery, which was also associated with conversion to total hip replacement. In short, older age, arthritic changes, longer duration of symptoms and worse pain scores before surgery correlated to poor outcomes of FAI surgery.

In my book ‘The Entrepreneurial Patient: A Patient’s Guide toHip Impingement’, you can read more about hip scores, arthritis scores, surgery expectations, the diagnostic workup for hip impingement and much more.

Another recently published article by Dr. Marc Philippon discussed hip labral repairs. He referenced one of his studies from 2009, stating that independent predictors of a better outcome included joint space greater than 2 mm and repair of labral tears instead of labral debridement. Dr. Philippon also stated that a successful labral repair may delay or prevent the development of osteoarthritis of the hip joint in the long term. However, more research is needed to assess how labral repairs affection the natural history of degenerative (arthritic) changes in the hip.

Browsing the web, it seems that left and right, people from many different camps claim that surgery to treat FAI will prevent osteoarthritis or that untreated FAI will lead to arthritis in the hip. I think that is generally a belief among many practitioners, but hard science data is still lacking to back up the assumption.

Another interesting research study looked at the relationship between two biomarkers and FAI.  The authors hypothesized that athletes with FAI would have elevated levels of C-reactive protein (CRP) and cartilage oligomeric matrix protein (COMP) compared to athletes who did not have FAI. C-reactive protein is a measure of inflammation. Both CRP and COMP are associated with osteoarthritis. When the researchers measured the blood levels of these two biomarkers, they found that the athletes who had FAI had a 24% increase in COMP levels and a 276% increase in CRP levels compared to the athletes who did not have FAI. The athletes with FAI also showed a decrease in hip disability and osteoarthritis scores (HOOS). (3)

The authors concluded that athletes with FAI demonstrate early biochemical signs of increased cartilage turnover and systemic inflammation. They went on to say that cartilage injury due to FAI might be reliably detected with biomarkers. In the future, such markers may be used as screening tools to identify at-risk patients and assess how effective hip preservation surgery may be at altering the natural history and progression to osteoarthritis.

Well, quite a few very well respected FAI surgeons co-authored this study. Sleuth here is not saying she’s smarter than they are, but can’t help but wondering how an elevation in COMP can with certainty be related to arthritis of the hip without scanning every other body part and ruling out arthritis in other joints. Also, CRP is a fairly unspecific inflammation marker. How could FAI surgeons be sure that there isn’t another inflammatory process in the body? There are also medicines, such as birth control pills, that elevate CRP. Just for checks and balances…

If hope you’re wiser than you started reading – until next time!

(1)  Saadat E, Martin SD, Thornhill TS, Brownlee SA, Losina E, Katz JN. Factors Associated With the Failure of surgical Treatment for Femoroacetabular Impingement: Review of the Literature. Am J Sports Med, 2013 Aug 30.

(2)  Marc J Philippon, Scott C. Faucet, Karen K. Briggs. Arthroscopic Hip Labral Repair.  Arthrosc Tech 2013 May; 2(2): e73-e76.

(3)  Bedi A, Lynch EB, Sibilsky Enselman ER, Davis ME, Dewolf PD, Makki TA, Kelly BT, Larson CM, Henning PT, Mendias CL. Elevation in Circulating Biomarkers of Cartilage Damage and Inflammation in Athletes With Femoroacetabular Impingement. Am J Sports Med. 2013 Aug 19.

1 comment:

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